Contrasting roles for IgM and B-cell MHCII expression in Brucella abortus S19 vaccine-mediated efficacy against B. melitensis infection

Brucellosis, caused by the bacterium Brucella, poses a significant global threat to both animal and human health. Although commercial live Brucella vaccines including S19, RB51, and Rev1 are available for animals, their unsuitability for human use and incomplete efficacy in animals necessitate the further study of vaccine-mediated immunity to Brucella. In this study, we employed in vivo B-cell depletion, as well as immunodeficient and transgenic mouse models, to comprehensively investigate the roles of B cells, antigen uptake and presentation, antibody production, and class switching in the context of S19-mediated immunity against brucellosis. We found that antibody production, and in particular secretory IgM plays a protective role in S19-mediated immunity against virulent Brucella melitensis early after the challenge in a manner associated with complement activation. While T follicular helper cell deficiency dampened IgG production and vaccine efficacy at later stages of the challenge, this effect appeared to be independent of antibody production and rather was associated with altered T-cell function. By contrast, B-cell MHCII expression negatively impacted vaccine efficacy at later timepoints after the challenge. In addition, B-cell depletion after vaccination, but before the challenge, enhanced S19-mediated protection against brucellosis, suggesting a deleterious role of B cells during the challenge phase. Collectively, our findings indicate antibody production is protective, while B-cell MHCII expression is deleterious, to live vaccine-mediated immunity against brucellosis.

IMPORTANCE

Brucella is a neglected zoonotic pathogen with a worldwide distribution. Our study delves into B-cell effector functions in live vaccine-mediated immunity against brucellosis. Notably, we found antibody production, particularly secretory IgM, confers protection against virulent Brucella melitensis in vaccinated mice, which was associated with complement activation. By contrast, B-cell MHCII expression negatively impacted vaccine efficacy. In addition, B-cell depletion after vaccination, but before the B. melitensis challenge, enhanced protection against infection, suggesting a detrimental B-cell role during the challenge phase. Interestingly, deficiency of T follicular helper cells, which are crucial for aiding germinal center B cells, dampened vaccine efficacy at later stages of challenge independent of antibody production. This study underscores contrasting and phase-dependent roles of B-cell effector functions in vaccine-mediated immunity against Brucella.

The challenge of managing ischemic stroke in brucellosis: a case report

A 64-year-old woman was admitted to the hospital for sudden weakness in one of her left limbs. The patient was diagnosed with acute ischemic stroke (IS) of undetermined cause and received intravenous thrombolysis. Following thrombolysis, the patient's left limb weakness improved, but she subsequently developed recurrent high fever and delirium. Further diagnostic tests revealed that she had been infected with Brucella melitensis. The patient showed significant improvement during anti-infection treatment for Brucellosis and secondary prevention treatment for IS. However, her condition unexpectedly worsened on the 44th day after admission due to a hemorrhagic stroke (HS), which required an urgent craniotomy. Immunohistochemical analysis of the hematoma sample collected during the operation showed the presence of CD4+ and CD8+ T lymphocytes surrounding the blood vessels. This case highlights the unique challenge of managing IS in brucellosis and sheds light on the potential role of T lymphocytes in the immune response related to stroke.

Brucella targets the host ubiquitin-specific protease, Usp8, through the effector protein, TcpB, for facilitating infection of macrophages

Brucella species are Gram-negative intracellular bacterial pathogens that cause the worldwide zoonotic disease brucellosis. Brucella can infect many mammals, including humans and domestic and wild animals. Brucella manipulates various host cellular processes to invade and multiply in professional and non-professional phagocytic cells. However, the host targets and their modulation by Brucella to facilitate the infection process remain obscure. Here, we report that the host ubiquitin-specific protease, USP8, negatively regulates the invasion of Brucella into macrophages through the plasma membrane receptor, CXCR4. Upon silencing or chemical inhibition of USP8, the membrane localization of the CXCR4 receptor was enriched, which augmented the invasion of Brucella into macrophages. Activation of USP8 through chemical inhibition of 14-3-3 protein affected the invasion of Brucella into macrophages. Brucella suppressed the expression of Usp8 at its early stage of infection in the infected macrophages. Furthermore, we found that only live Brucella could negatively regulate the expression of Usp8, suggesting the role of secreted effector protein of Brucella in modulating the gene expression. Subsequent studies revealed that the Brucella effector protein, TIR-domain containing protein from Brucella, TcpB, plays a significant role in downregulating the expression of Usp8 by targeting the cyclic-AMP response element-binding protein pathway. Treatment of mice with USP8 inhibitor resulted in enhanced survival of B. melitensis, whereas mice treated with CXCR4 or 14-3-3 antagonists showed a diminished bacterial load. Our experimental data demonstrate a novel role of Usp8 in the host defense against microbial intrusion. The present study provides insights into the microbial subversion of host defenses, and this information may ultimately help to develop novel therapeutic interventions for infectious diseases.

A multi-epitope subunit vaccine based on CU/ZN-SOD, OMP31 and BP26 against Brucella melitensis infection in BALB/C mice

Brucellosis, a zoonosis caused by Brucella, is highly detrimental to both humans and animals. Most existing vaccines are live attenuated vaccines with safety flaws for people and animals. Therefore, it is advantageous to design a multi-epitope subunit vaccine (MEV) to prevent Brucella infection. To this end, we applied a reverse vaccinology approach. Six cytotoxic T cell (CTL) epitopes, seven T helper cell (HTL) epitopes, and four linear B cell epitopes from CU/ZN-SOD, Omp31, and BP26 were obtained. We linked the CTL, HTL, B-cell epitopes, the appropriate CTB molecular adjuvant, and the universal T helper lymphocyte epitope, PADRE, with linkers AAY, GPPGG, and KK, respectively. This yielded a 412-amino acid MEV construct, which we named MEVcob. The immunogenicity, stability, safety, and feasibility of the construct were evaluated by bioinformatics tools (including the AlphaFold2 prediction tool, the AlphaFold2 tool, NetMHC-I pan 4.0 server, IEDB MHC-I server, ABCpred service, and C-ImmSim server); the physicochemical properties, secondary and tertiary structures, and binding ability of MEVocb to toll-like receptor 4 (TLR4) was analyzed. Then, codon adaptation and computer cloning studies were performed. MEVocb is highly immunogenic in immunostimulation experiments, The proteins translated by these sequences were relatively stable, exhibiting a high antigenic index. Furthermore, mouse experiments confirmed that the MEVocb construct could raise IFN-γ, IgG, IgG2a, IgG1, IL-2, TNF-α levels in mice, indicating that induced a specific humoral and cellular immune response in BALB/c mice. This vaccine induced a statistically significant level of protection in BALB/c mice when challenged with Brucella melitensis 043 in Xinjiang. Briefly, we utilized immunoinformatic tools to design a novel multi-epitope subunit candidate vaccine against Brucella. This vaccine aims to induce host immune responses and confer specific protective effects. The study results offer a theoretical foundation for the development of a novel Brucella subunit vaccine.

Prevalence of Brucella melitensis and Brucella abortus Fluoroquinolones Resistant Isolates: A Systematic Review and Meta-Analysis

Background: Brucellosis impact both animals and humans worldwide. However, using antibiotics for brucellosis remains controversial despite decades of research. Relapse can complicate treatment in this area. Since the mid-1980s, microbiologists, and physicians have studied fluoroquinolones' use for treating human brucellosis. The principal advantages of fluoroquinolones are their intracellular antimicrobial activity, low nephrotoxicity, good pharmacokinetics, and the lack of drug-level monitoring. Fluoroquinolones inhibit disease recurrence. In vitro and clinical data were used to study the prevalence of Brucella melitensis and Brucella abortus fluoroquinolone-resistant isolates. Methods: The PubMed, Scopus, Embase, and Web of Science databases were carefully searched until August 6, 2022, for relevant papers. The number of resistant isolates and sample size were used to estimate the proportion of resistant isolates, fitting a model with random effects, and DerSimonian-Laird estimated heterogeneity. Furthermore, meta-regression and subgroup analyses were used to assess the moderators to identify the sources of heterogeneity. Meta-analysis was performed using R software. Results: Forty-seven studies evaluated fluoroquinolone resistance in Brucella spp. Isolates. Fluoroquinolones have shown high in vitro efficacy against Brucella spp. The resistance rates to ofloxacin, sparfloxacin, fleroxacin, pefloxacin, and lomefloxacin were 2%, 1.6%, and 4.6%, respectively. Conclusion: Clinical in vitro tests demonstrated that fluoroquinolones can eradicate Brucella spp. Owing to first-line medication resistance, recurrence, and toxicity, it is essential to standardize the Brucella antimicrobial susceptibility test method for a more precise screening of resistance status. Fluoroquinolones are less resistant to fluoroquinolone-based treatments in modern clinical practice as alternatives to standard therapy for patients with brucellosis relapse after treatment with another regimen and in patients who have developed toxicity from older agents.

Nano and microparticle drug delivery systems for the treatment of Brucella infections

Nano-based drug delivery systems are increasingly used for diagnosis, prevention and treatment of several diseases, thanks to several beneficial properties, including the ability to target specific cells or organs, allowing to reduce treatment costs and side effects frequently associated with chemotherapeutic medications, thereby improving treatment compliance of patients. In the field of communicable diseases, especially those caused by intracellular bacteria, the delivery of antibiotics targeting specific cells is of critical importance to maximize their treatment efficacy. Brucella melitensis, an intracellular obligate bacterium surviving and replicating inside macrophages is hard to be eradicated, mainly because of the low ability of antibiotics to enter these phagocityc cells . Although different antibiotics regimens including gentamicin, doxycycline and rifampicin are in fact used against the Brucellosis, no efficient treatment has been attained yet, due to the intracellular life of the respective pathogen. Nano-medicines responding to environmental stimuli allow to maximize drug delivery targeting macropages, thereby boosting treatment efficacy. Several drug delivery nano-technologies, including solid lipid nanoparticles, liposomes, chitosan, niosomes, and their combinations with chitosan sodium alginate can be employed in combination of antibiotics to successfully eradicate Brucellosis infection from patients.

Evaluation of frequency of antibodies against Neospora caninum, Toxoplasma gondii and Brucella melitensis, risk factors and spatial distribution of infection in goat and sheep flocks from Argentina

Neospora caninum, Toxoplasma gondii and Brucella melitensis are pathogens that cause abortion in small ruminants. Besides, B. melitensis and T. gondii are zoonotic pathogens. The aim of this study was to describe the frequency of antibodies against N. caninum, T. gondii and B. melitensis in sheep and goats from three provinces of the center region of Argentina. In addition, the spatial distribution of the infected flocks/herds and risk factors were evaluated. A cross-sectional study was conducted from 2015 through 2016. Serum samples from 4783 goats and 1524 sheep from 186 goat, 51 sheep and 38 mixed flocks/herds were analyzed. Competitive inhibition enzyme-linked immunosorbent assay (ciELISA) and indirect fluorescent antibody test (IFAT) were performed for detection of antibodies against N. caninum and IFAT for T. gondii. The buffered plate antigen test and complement fixation test were performed for detection of antibodies against B. melitensis. The frequency of anti-T. gondii antibodies was 41.2% and 29.7% for sheep and goats, respectively. The frequency of anti-N. caninum antibodies was 17.2% and 14% for sheep and goats, respectively. About 97.1% of the sheep flocks, 79.4% of the goat herds and the 91.3% of the mixed flocks had seropositive animals to T. gondii. About 61.8% of the sheep flocks, 58% of the goat herds and the 82.6% of the mixed flocks had seropositive animals to N. caninum. All the analyzed animals were negative to anti-B. melitensis antibodies. For T. gondii, a significant cluster of high risk of seropositive flocks/herds was detected in the littoral of the Parana River. The province of origin of the flock/herd was the only variable associated to T. gondii positivity (p = 0.003). Animals from Santiago del Estero and Santa Fe Provinces had 3.48 and 1.77 times more risk to be positive to T. gondii than animals from Entre Ríos Province, respectively. For N. caninum, a cluster of high risk of seropositive flocks/herds was detected in the north of Santa Fe Province. The only explanatory variable associated to N. caninum positivity was animal species (p = 0.003). Sheep had 1.73 times more risk to be positive to N. caninum than goats. The absence of antibodies against B. melitensis in all the analyzed animals is an important finding for the public health of the region. Since bordering provinces have infected flocks/herds, brucellosis in small ruminants should be under epidemiologic surveillance in the region.

High Seropositivity of Brucella melitensis Antibodies among Pregnant Women Attending Health Care Facilities in Mwanza, Tanzania: A Cross-Sectional Study

Background

Brucellosis is one of the most prevalent zoonotic neglected tropical diseases across the globe. Brucella melitensis (B. melitensis), the most pathogenic species is responsible for several pregnancy adverse outcomes in both humans and animals. Here, we present the data on the magnitude of B. melitensis antibodies among pregnant women in Mwanza, Tanzania, the information that might be useful in understanding the epidemiology of the disease and devising appropriate control interventions in this region. Methodology. A hospital-based cross-sectional study involving pregnant women was conducted at two antenatal clinics in Mwanza between May and July 2019. The pretested structured questionnaire was used for data collection. Blood samples were collected aseptically from all consenting women followed by the detection of B. melitensis antibodies using slide agglutination test. Descriptive data analysis was done using STATA version 17.

Results

A total of 635 pregnant women were enrolled with the median age of 25 (interquartile range (IQR): 16-48) years and median gestation age of 21 (IQR: 3-39) weeks. Seropositivity of B. melitensis antibodies was 103 (16.2 (95% CI:13.3-19.1)). On the multivariate logistic regression analysis, as the gestation age increases, the odds of being seropositive decreases (aOR:0.972 (95% CI: 0.945-0.999), P = 0.045). Furthermore, being a housewife (aOR:3.902 (95% CI:1.589-9.577), P = 0.003), being employed (aOR:3.405 (95% CI:1.412-8.208), P = 0.006), and having history of miscarriage (aOR:1.940 (95% CI:1.043-3.606), P = 0.036) independently predicted B. melitensis seropositivity among pregnant women in Mwanza.

Conclusion

High seropositivity of B. melitensis was observed among employed and housewife pregnant women in Mwanza. This calls for the need of more studies in endemic areas that might lead to evidence-based control interventions.

Molecular Investigation of Brucella Species Belongs to Sheep and Goats in Seropositive Samples from an Endemic Area of Hamedan Province; Famenin Brucellosis Cohort Study

Brucellosis is a zoonotic infectious disease in western regions of Iran, especially in Hamedan province. Following the Famenin brucellosis cohort study, the main aim of the current study was the molecular detection of Brucella species (spp.) in sheep and goats from Famenin, Hamedan, Iran. A total of 23 Brucella-seropositive samples (sheep=21 and goats=2), which had been screened from 1,660 animals in the Famenin cohort study, were used to detect Brucella-DNA using the BCSP31 target gene and IS711 locus. In total, 20 of 23 samples were positive for Brucella infection by using specific primers. Additionally, Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) were confirmed in 90% (n=18) and 10% (n=2) of positive samples, respectively. There was no sample with the co-infection of B. abortus and B. melitensis. In this study, B. abortus was isolated from one of the goat samples. This is the first report on Brucella spp. in animals in the region. It was found that B. melitensis is the dominant spp. responsible for brucellosis in animals from Famenin. Molecular techniques are reliable tools to detect Brucella infection, especially in cases without serology findings and conclusive results.

Exosomes released by Brucella-infected macrophages inhibit the intracellular survival of Brucella by promoting the polarization of M1 macrophages

Exosomes, membrane vesicles released extracellularly from cells, contain nucleic acids, proteins, lipids and other components, allowing the transfer of material information between cells. Recent studies reported the role of exosomes in pathogenic microbial infection and host immune mechanisms. Brucella-invasive bodies can survive in host cells for a long time and cause chronic infection, which causes tissue damage. Whether exosomes are involved in host anti-Brucella congenital immune responses has not been reported. Here, we extracted and identified exosomes secreted by Brucella melitensis M5 (Exo-M5)-infected macrophages, and performed in vivo and in vitro studies to examine the effects of exosomes carrying antigen on the polarization of macrophages and immune activation. Exo-M5 promoted the polarization of M1 macrophages, which induced the significant secretion of M1 cytokines (tumour necrosis factor-α and interferon-γ) through NF-κB signalling pathways and inhibited the secretion of M2 cytokines (IL-10), thereby inhibiting the intracellular survival of Brucella. Exo-M5 activated innate immunity and promoted the release of IgG2a antibodies that protected mice from Brucella infection and reduced the parasitaemia of Brucella in the spleen. Furthermore, Exo-M5 contained Brucella antigen components, including Omp31 and OmpA. These results demonstrated that exosomes have an important role in immune responses against Brucella, which might help elucidate the mechanisms of host immunity against Brucella infection and aid the search for Brucella biomarkers and the development of new vaccine candidates.

The outer membrane proteins based seroprevalence strategy for Brucella ovis natural infection in sheep

Introduction

The diagnosis of brucellosis largely relies on tiger red plate agglutination test (RBPT). However, it is difficult to distinguish between natural infection antibody positive and vaccination antibody positive, nevertheless, the identification of specific Brucella species natural infection.

Methods

Here, we analyzed the structure of main outer membrane proteins (OMPs), OMP25 and OMP31 from Brucella ovis (B. ovis) and Brucella melitensis (B. melitensis), which are the main pathogens of sheep brucellosis, and found the OMP25 and OMP31 could be used as the differential antigens for B. ovis and B. melitensis antibody. Then we expressed the OMP25 from B. ovis (OMP25o) and OMP31 from B. melitensis (OMP31m).

Results

They have equally efficiency in antibody detection of vaccinated sheep serum, consistent with the RBPT results. However, through epidemiological investigations, we found some RBPT positive samples were negative by the OMP31m based serum antibody detection, but these samples gave positive results by the OMP25o. We verified these OMP31m negative but OMP25o positive samples by B. ovis and B. melitensis specific primers based PCR detection, and all these samples were B. melitensis negative. However, four out of six samples are B. ovis positive. These results showed that we could use the OMP25o and OMP31m to diagnose sheep brucellosis antibody, especially to discriminate the infection of the B. ovis.

Discussion

Currently, China has not yet approved a vaccine based on B. ovis and B. ovis positive samples should be naturally infected. There should be some implicit transmission of B. ovis in Jilin province. Further epidemiological investigation should be conducted to monitor the B. ovis natural infection.

Multi-Epitope Vaccine Candidates Associated with Mannosylated Chitosan and LPS Conjugated Chitosan Nanoparticles Against Brucella Infection

One promising approach to increase protection against infectious diseases is to use adjuvants that can selectively stimulate the immune responses. In this study, multi-epitope antigens associated with LPS loaded chitosan (LLC) as toll-like receptor agonist or mannosylated chitosan nanoparticle (MCN) as vaccine delivery system were evaluated for their ability to stimulate immune responses to Brucella infection in mice model. Our results indicated that the addition of MCN to our vaccine formulations significantly elicited IFN-γ and IL-2 cytokines and antibody titers, in comparison with the non-adjuvanted vaccine candidates. The present results indicated that multi-epitopes and their administration with LLC or MCN induced Th1 immune response. In addition, vaccine candidates containing MCN provided high percentage of protection against B. melitensis and B. abortus infection. Our results provided support to previous reports indicating that MCNs are attractive adjuvants and addition of this adjuvant to multi-epitopes antigens play an important role in the development of vaccine against Brucella.

Clearance of bacteria from lymph nodes in sheep immunized with Brucella suis S2 vaccine is associated with M1 macrophage activation

Ovine brucellosis is a global zoonotic disease of sheep caused by Brucella melitensis, which inflicts a significant burden on human and animal health. Brucella suis strain S2 (B. suis S2) is a smooth live attenuated vaccine for the prevention of ovine brucellosis in China. However, no previous studies have assessed the immunogenicity of B. suis S2 vaccine after oral immunization in sheep. Here, we attempted to evaluate the ovine immune response over the course of B. suis S2 immunization and to identify in vivo predictors for vaccine development. Body temperature, serum Brucella antibodies, serum cytokines (IL-12p70 and interferon [IFN]-γ), and bacterial load in the mandibular lymph nodes (LN), superficial cervical LN, superficial inguinal LN, and spleen were investigated to determine the safety and efficacy of the vaccine. The abnormal body temperature of sheep occurred within 8 days post-infection (dpi). Brucella suis S2 persisted for a short time (< 21 dpi) in the mandibular LN. The highest level of IL-12p70 was observed at 9 dpi, whereas serum IFN-γ levels peaked at 12 dpi. Transcriptome analysis and quantitative reverse transcription PCR were performed to determine gene expression profiles in the mandibular LN of sheep. Antigen processing and presentation pathway was the dominant pathway related to the dataset. Our studies suggest that the immune response in ovine LN resembled type 1 immunity with the secretion of IL-12p70 and IFN-γ after B.suis S2 immunization and the vaccine may eliminate Brucella via stimulation of M1 macrophages through the course of Th cells.

Evaluation of the goat cellular immune response to rBtuB-Hia-FlgK peptides from Brucella melitensis

Brucellosis is a zoonosis caused by Brucella; B. melitensis is the most prevalent species in goats and humans. Previously, three B. melitensis peptides, rBtuB-Hia-FlgK showed antigen-specific immune responses in rodent models. The goal of this study was to evaluate the goat Th1/Th2 immune response to B. melitensis peptides. Twenty-eight animals were separated into four groups and were immunized with the rBtuB-Hia-FlgK peptides cocktail, adjuvant, PBS and Rev-1 vaccine, respectively. Peripheral blood samples were collected on days 0, 15, and 80 post-inoculation. The CD4+ and CD8+ T cells proliferation, and cytokine production of the Th-1 (IL-2, IL-12, TNF-α, and IFN-γ) and Th-2 profiles (IL-4, IL-5, and IL-10) were evaluated. An increase of CD4+/CD8+ at 15 days post-vaccination was observed and continued until the 80th. In addition, the IFN-γ, TNF-α, and IL-2 mRNA expression were typically induced by the 15th day, but only IFN-γ levels were observed at day 80 post-immunization. Brucella pathogenesis is distinguished by the presence of a large amount of Th-1 cytokines. Although a reduced amount of IFN-γ in the culture supernatant was accurately detected compared with Rev-1 after 15 days, it could be influenced by the sampling schedule, as a higher cytokine production might be induced as early as the first-week post-vaccination. The results indicate that rBtuB-Hia-FlgK induced an immune response similar to the Rev-1 vaccine. The possible use of inert molecules with the unique ability to typically induce cellular response similar to attenuated vaccine represents an attractive option that should not be ruled out.

Brucellosis in older person: a case report from Qatar

BACKGROUND

Brucellosis is a multisystem disease with a broad spectrum of non-specific symptoms that generally occur within three weeks but sometimes up to 3 months after inoculation. Human brucellosis is quite uncommon in Elderly in Qatar.

CASE REPORT

This report describes a case of Brucellosis in acute geriatric unit under Rumailah Hospital in Qatar. The patient was an 81-year-old Qatari Gentle man, functionally able to walk with minimal assistance and had mild cognitive impairment who presented with high-grade fever with chills, anorexia, low back pain and arthralgia for 10 days. The above complaints occurred often for 1 month and had fever intermittently. Lab investigations revealed as high CRP 117 mg/l, low Hb 9.1 g/dl and mild elevation in ALP (151 µ/l) with normal leukocyte and platelet count. His blood culture positive for Brucella melitensis with high brucella Antibody titter 1:1280. The diagnosis made as Brucellosis.

DISCUSSION

The clinical manifestations of Brucellosis are fever, night sweating, chills, arthralgia and loss of appetite. It seems pyrexia of unknown origin without other symptoms is most common presentation of Brucellosis in old age. The confirmation of Brucellosis made with serological tests, with significantly high titer, in the presence or absence of blood culture. Brucella antibody titers (≥1:160) are suggestive of active infection. Anemia and raised CRP and liver enzymes were the most prominent laboratory abnormalities in our patients. Previous study from Qatar reported that 41.7% had a history of raw milk consumption and 12.5% had a history of animal contact. The objectives of Brucellosis treatment include the prevention of complications and relapse.

CONCLUSION

Our case presented with classical symptoms and received appropriate treatment on time. However, atypical clinical presentation and lack of specific history taking can delay diagnosis and treatment; it leads to serious clinical disease progression with increased complications. From this case study, we would contribute to optimal assessment and to keep differential diagnosis for unknown cause of fever can be Brucellosis in geriatric population.

A health promotion perspective for the control and prevention of Brucellosis (Brucella melitensis); Israel as a case study

Background

Brucellosis (Brucella melitensis) is endemic in many countries around the world, therefore, identifying what is required to control and prevent the disease is essential. The health promotion concept and five areas of action, presented in the Ottawa Charter (1986) may help understand how to go forward in the prevention of the disease. Israel serves as a case study.

Aim

To identify barriers to the control and prevention of brucellosis (Brucella melitensis) in Israel by analyzing trends in incidence in conjunction with interventions implemented over the last seven decades, applying the health promotion areas of action.

Methods

1. A document review approach was adopted to develop a list of interventions implemented in Israel to prevent and control brucellosis and identify barriers to implementation. These were analysed using the health promotion areas of action. 2. Data from the mandatory reporting of infectious diseases in Israel regarding brucellosis in humans between 1951 and 2021 are presented and analyzed in conjunction with the interventions implemented.

Results

A large range of interventions were implemented following outbreaks of the disease. These interventions followed the health promotion areas of action, including mainly: policy, education and environment and brought about a decrease in the disease among both animals and humans. However, major interventions were discontinued after a few years. In addition, we identified some areas of action that could be much improved on. The interventions, in many cases were not simultaneously implemented or coordinated, decreasing the chances of them having the expected long term impact.

Conclusions

Control and prevention of the disease in Israel is partial. Areas of action that could be improved include enforcement of regulations, strengthening community action and improving personal skills. Simultaneous and continuous implementation of the interventions may achieve the goals of sustained prevention and control. There seems to be a lack of a long-term strategy and an integrated holistic intervention approach that may contribute to the control and prevention of the disease.

abortus: Harnessing an epitope mapping and immunoinformatics approach

Vaccines against Brucella abortus, B. melitensis and B. suis have been based on weakened or killed bacteria, however there is no recombinant vaccine for disease prevention or therapy. This study attempted to predict IFN-γ epitopes, T cell cytotoxicity, and T lymphocytes in order to produce a multiepitope vaccine based on BtpA, Omp16, Omp28, virB10, Omp25, and Omp31 antigens against B. melitensis, B. abortus, and B. suis. AAY, GPGPG, and EAAAK peptides were used as epitope linkers, while the PADRE sequence was used as a Toll-like receptor 2 (TLR2) and TLR4 agonist. The final construct included 389 amino acids, and was a soluble protein with a molecular weight of 41.3 kDa, and nonallergenic and antigenic properties. Based on molecular docking studies, molecular dynamics simulations such as Gyration, RMSF, and RMSD, as well as tertiary structure validation methods, the modeled protein had a stable structure capable of interacting with TLR2/4. As a result, this novel vaccine may stimulate immune responses in B and T cells, and could prevent infection by B. suis, B. abortus, and B. melitensis.

Primary and memory immune responses against rough Brucella canis are less robust compared to smooth B. abortus and B. melitensis following intratracheal infection in mice

Brucella canis is the cause of canine brucellosis, a globally distributed, zoonotic pathogen which primarily causes disease in dogs. B. canis is unique amongst the zoonotic Brucella spp. with its rough lipopolysaccharide, a trait typically associated with attenuation in gram-negative bacteria. Unfortunately, no vaccine is available against B. canis, and vaccine development is hampered by a limited understanding of the immune response required to combat it and the course of infection following a physiologically relevant, mucosal route of inoculation. To address these concerns and analyze the impact of the rough phenotype on the immune response, we infected mice intratracheally with rough B. canis or smooth B. melitensis or B. abortus. Bacterial colonization and histologic lesions were assessed in systemic target organs as well as locally in the lungs and draining mediastinal lymph node. Mice were also reinfected with Brucella following antibiotic treatment and cytokine production by T lymphocytes in the lung and spleen was assessed by flow cytometry to investigate the memory immune response. Despite its rough phenotype, B. canis established a persistent infection at the same level of colonization as the smooth strains. However, B. canis induced significantly less granulomatous inflammation in the spleen as well as a lack of bronchial-associated lymphoid tissue (BALT) hyperplasia in the lungs. These differences coincided with increased IL-10 and decreased IFN-γ in the spleen of B. canis-infected mice. Previous exposure to all Brucella strains provided protection against colonization following secondary challenge, although induction of IFN-γ by T lymphocytes was seen only in the lungs during B. canis infection while the smooth strains induced this cytokine in the spleen as well. Neither Brucella strain induced significant polyfunctional T lymphocytes, a potential immunomodulatory mechanism that appears to be independent of lipopolysaccharide phenotype.

Using a Relative Quantitative Proteomic Method to Identify Differentially Abundant Proteins in Brucella melitensis Biovar 3 and Brucella melitensis M5-90

Brucellosis, caused by Brucella spp., is one of the most widespread bacterial zoonoses worldwide. Vaccination is still considered the best way to control brucellosis. An investigation into the differential proteome expression patterns of wild and vaccine strains may help researchers and clinicians differentiate between the strains to diagnose and better understand the mechanism(s) underlying differences in virulence. In the present study, a mass spectrometry-based, label-free relative quantitative proteomics approach was used to investigate the proteins expressed by the wild strain, B. melitensis biovar 3 and compare it with those expressed by B. melitensis M5-90. The higher level of virulence for B. melitensis biovar 3 compared to B. melitensis M5-90 was validated in vitro and in vivo. A total of 2133 proteins, encompassing 68% of the theoretical proteome, were identified and quantified by proteomic analysis, resulting in broad coverage of the B. melitensis proteome. A total of 147 proteins were identified as differentially expressed (DE) between these two strains. In addition, 9 proteins and 30 proteins were identified as unique to B. melitensis M5-90 and B. melitensis biovar 3, respectively. Pathway analysis revealed that the majority of the DE proteins were involved in iron uptake, quorum sensing, pyrimidine metabolism, glycine betaine biosynthetic and metabolic processes, thiamine-containing compound metabolism and ABC transporters. The expression of BtpA and VjbR proteins (two well-known virulence factors) in B. melitensis biovar 3 was 8-fold and 2-fold higher than in B. melitensis M5-90. In summary, our results identified many unique proteins that could be selected as candidate markers for differentiating vaccinated animals from animals with wild-type infections. BtpA and VjbR proteins might be responsible for the residual virulence of B. melitensis M5-90, while ABC transporters and thiamine metabolism associated proteins may be newly identified Brucella virulence factors. All of the identified DE proteins provide valuable information for the development of vaccines and the discovery of novel therapeutic targets.

Evaluation of in vitro Anti-Brucella Activity and Chemical Composition of Different Geographically Distinct Propolis from Iran

Brucellosis is one of the most important zoonotic diseases in many regions worldwide. This study aimed to investigate the antimicrobial properties of hydro-ethanolic extracts of propolis (EEP) samples collected from six different regions of Iran against five Brucella melitensis (B. melitensis) clinical isolates causing human brucellosis and an antibiotic-resistant B. abortus vaccinal strain (RB51). Brucella clinical isolates were first carefully identified using conventional molecular typing and Brucella bio-typing methods. Different Brucella strains were then confronted with EEPs using the disk-diffusion agar method to evaluate the antimicrobial activity of each propolis extract. Chemical composition of EEPs was then determined using HPLC-DAD, and the main phenolic compounds were quantified. It was found that all EEPs displayed significant antimicrobial activities against Brucella strains, though to varying extents. All tested clinical strains were susceptible to different EEPs with inhibition zones ranging from 18 to 38 mm diameter. Interestingly, the RB51 vaccine strain was more susceptible to EEP6 (from Markazi province), compared to conventional antibiotics used in the treatment of brucellosis. Substantial differences observed in EEP antimicrobial activity could be due to their distinct botanical origins and chemical compositions as confirmed by our HPLC analysis. The promising inhibitory effect of some propolis preparations against a broad spectrum of Brucella strains points to the need for further studies in the context of systematic clinical investigations and opens up the way for the development of natural complements in support of conventional antibiotic therapy.

Evaluation of the immunogenicity and efficacy of a chimeric OMP25-OMP31 antigen in BALB/c mice

Brucellosis is a zoonotic disease causes by Brucella bacteria. So far, there is not any efficient treatment for this infectious disease in animals, although subunit vaccines can be a safe alternative. To this aim, we have designed a new chimeric OMP25-OMP31 antigen formulated in Chitosan nanoparticles and studied its protective efficiency in vivo. OMP25-OMP31 was produced using spliced overlap extension by polymerase chain reaction and the 3D protein structure and antigenic ability were predicted using computational tools. In addition, the humoural and cellular immune responses were measured by ELISA in six different experimental groups. The immune response showed chimeric rOMP25-OMP31 antigen-induced higher titers of IFN-γ and TNF-α cytokines, while the lowest amount of IL-4 was dedicated to itself. Also, rOMP25-OMP31 stimulated higher titer of IgG than individual injection of rOMP25 and rOMP31 treatments and the cell proliferation assay demonstrated the vaccination with rOMP25-OMP31 elicits a vigorous antigen-specific cell proliferative. In addition, the challenge experiment showed immunised mic stimulated a higher level of protection than negative controls. Overall, the results of rOMP25-OMP31 could be promising for considering chimeric constructs as a feasible vaccine candidate for further investigations against brucellosis.

Brucellosis Outbreak Traced to Commercially Sold Camel Milk through Whole-Genome Sequencing, Israel

Brucellosis, a neglected zoonotic disease acquired from contaminated food products, remains a public health concern worldwide. We describe an outbreak in which commercially sold camel milk containing Brucella melitensis was distributed across Israel. Whole-genome sequencing linked patients infected with B. melitensis to wholesale camel milk and unregulated livestock trade.

Brucellosis in Iranian livestock: A meta-epidemiological study

Brucellosis is a widespread zoonotic disease affecting human and livestock health. This meta-epidemiological study is aiming to draw a comprehensive picture of the Brucella prevalence in Iranian livestock, trying to estimate most affected subgroups as well as the most appropriate methods and sampling conditions for brucellosis screening programs. A literature search was performed among data published between 1 January 1970 and July 2020. Different subgroups were compared according to animal species, gender, age, sampling season, sampling locations as well as the diagnostic method used for brucellosis screening. To determine heterogeneity of studies, Chi-squared test was used and a random effect model (REM) estimated the pooled prevalence among subgroups. A total of 45 publications, comprising 240 studies/data-reports, were evaluated. A significant increase in the number of studies was found over time (Coefficient = 0.151, p value < 0.001). The most studied species in Iran was cow (n = 75), followed by sheep (n = 63), goat (n = 45), camel (n = 40) and Buffalo (n = 16). The most identified Brucella species in livestock were Brucella melitensis (n = 50), Brucella abortus (n = 39), mix infection of B. melitensis and B. abortus (n = 11) and vaccine strain of B. melitensis Rev1 (n = 4). PCR-based tests were the most common applied diagnostic method (n = 140), while the highest prevalence rate of positive samples was obtained by indirect ELISA (69%). The prevalence of brucellosis was significantly higher in females (10.91%) compared to males (8.23%). The meta-epidemiological study of brucellosis in Iranian livestock would help to strengthen surveillance, control and prevention approaches to counter the spread of this zoonotic disease.

Abortion and various associated risk factors in dairy cow and sheep in Ili, China

We studied livestock abortion and various associated risk factors in the Ili region of northwest China. Livestock abortion prevalence was estimated and correlated with infections (Brucellosis, Salmonellosis, Mycoplasma and Chlamydia seropositivity) and management (farming type and contact with other herds/flocks) risk factors. A total of 2996 serum samples (1406 cow, 1590 sheep) were identified by RBPT (Rose Bengal Plate Test) and c-ELISA (competitive-enzyme linked immunosorbent assay), and they showed the overall seroprevalence of brucellosis in the study area was cow 6.76%, sheep 9.50%. The seroprevalence of brucellosis in X county was cow 7.06%, sheep 9.12%; in H county was cow 11.70%, sheep 10.80%; and in Q county was cow 4.22%, sheep 9.11%. The overall seroprevalence of Mycoplasma in the study area was cow 3.20%, sheep 6.42%. The seroprevalence of Mycoplasma in X county was cow 3.39%, sheep 7.98%; in H county was cow 5.26%, sheep 9.97%; and in Q county was cow 2.11%, sheep 4.33%. The Odds ratio of brucellosis for cow and sheep, respectively, were 45.909 [95% CI 26.912-78.317, P<0.001] and 70.507 [95% CI 43.783-113.544, P<0.001] times higher than other abortion-related factors including mixed farming, contact with other flocks and Mycoplasma infection. A total of 54 samples, including aborted cow (22), sheep (30) fetuses and milk samples (2), were identified as Brucella melitensis (B. melitensis) positive. A total of 38 Brucella were isolated from 16 aborted cow, 20 sheep fetuses and 2 milk samples. All of these isolates were identified, and confirmed, as B. melitensis. A phylogenetic tree showed that the Brucella isolates closely matched the B. melitensis biovar 3 isolated in Inner Mongolia, China, and B. melitensis isolated from Norway and India. These results suggest that B. melitensis biovar 3 is the main pathogen responsible for cow and sheep abortion and also pose a human health risk. Additionally, livestock reproduction can also be influenced by Mycoplasma infection and managerial factors (farming type and contact with other herds/flocks), especially in remote areas.

Functionalization of anti-Brucella antibody based on SNP and MNP nanoparticles for visual and spectrophotometric detection of Brucella

An Immuno-Nano-Biosensor with high sensitivity was designed based on iron and silica nanoparticles to detect B. abortus. Briefly explain, primary polyclonal antibody (IgG₁) was conjugated on surface magnetic nanoparticles (MNPs) to form MNP-IgG₁. Secondary polyclonal antibody (IgG₂) and Horseradish Peroxidase enzyme were conjugated on silica nanoparticles (SNPs) to form HRP-SNP-IgG₂. HRP-SNP-IgG₂. MNP-IgG₁ and HRP-SNP-IgG₂ were added to B. abortus. The MNP-IgG₁-B.abortus-IgG₂-SNP-HRP complex was isolated from the reaction mixture using a magnet. After that, tetramethylbenzidine was added to the complex. The reaction was stopped with HCl and investigated using UV-Vis spectrophotometry. The nanoparticles' structure and size were investigated using SEM and DLS. Immuno-Nano-Biosensor sensitivity and specificity were determined. The SEM and DLS results indicated that the SNPs, MNPs, HRP-SNP-IgG₂ and MNP-IgG₁ size and structure were 35, 44, 60 and 56 nm, respectively. In addition, a good linear correlation was observed at 10²-10⁷ CFU mL^-1 concentrations, which their linear equation and regression were Y = 0.3× + 0.18 and R² 0.982, respectively. The limitation of detecting B. abortus was 160 CFU mL^-1. Finally, the results demonstrated that those designed Immuno-Nano-Biosensor could be specifically detected B. abortus and B. melitensis in real samples.

Scrotal enlargement in rams and bucks in Qassim region, central of Saudi Arabia: clinical and ultrasonographic findings and seroprevalence of brucellosis

The aim of this study was to clarify the causes of scrotal enlargement in rams and bucks in Qassim region of Saudi Arabia. Enlarged scrotal contents of rams and bucks (n = 153) were examined by visual inspection, palpation, and ultrasonography. Blood samples were obtained and tested for Brucella sp. infection. Clinical and ultrasonographic findings showed that scrotal enlargement was mainly associated with orchitis, peri-orchitis, and epididymitis. Miscellaneous findings were scrotal hernia, scrotal hematoma, and hydrocele. The frequencies of orchitis, peri-orchitis, and epididymitis were 47.4, 21.1, and 14.1% in Awassi rams; 54.5, 21.7, and 8.7% in Najdi rams; 52.3, 20.5, and 9.1% in Ardi bucks; and 50, 16.7, and 16.7% in Damascus bucks, respectively. Orchitis was associated with no-abscess formation (23%), single-abscess formation (15.4%), and multiple-abscesses formation (61.6%). Peri-orchitis was characterized by hard consistency, atrophy of the testes, and extensive connective tissue formation. Epididymitis was observed mainly at the tail of the epididymis (82.4%) but rarely at the head (17.6%). Epididymitis was associated in many cases with abscessation (70.6%). Males with orchitis, peri-orchitis, and epididymitis were positive for Brucella melitensis and Brucella ovis in the frequency of 21.3% and 48.8%, respectively. In conclusion, scrotal enlargement in rams and bucks in Qassim region is caused mainly by inflammation of the testis and/or epididymis and associated tremendously with brucellosis seropositivity.

Outbreak of Brucella melitensis infection in Eastern Sicily: risk factors, clinical characteristics and complication rate

Brucellosis is one of the most common zoonoses in the world, especially in Southern Italy, where many cases are still recorded every year. 128 cases of brucellosis were observed in Messina (Sicily) in 2016, representing a tenfold increase in the number of cases of brucellosis expected. The aim of this multicenter retrospective study was to analyze clinical and microbiological aspects of a brucellosis outbreak in the province of Messina in 2016, the incidence of its complications and the treatment combinations applied. The principal transmission route was through the ingestion of unpasteurized fresh cheese. The mean latency period between the onset of the symptoms and diagnosis was 35.58±42.75 days. A late diagnosis increases the risk of developing complications. Drug-resistant strains of B. melitensis to Trimethoprim/ Sulfamethoxazole and Ciprofloxacin were found in blood cultures of 58.4% patients. Brucellosis is still present in Sicily. A diagnostic delay predisposes to complications requiring prolonged therapies. The finding of Brucella melitensis strains resistant to the most widespread treatments is worrisome and needs further investigation. Moreover, the use of alternative combination antibiotic therapy is recommended.

The economic efficiency and equity of government policies on brucellosis: comparative insights from Albania and the United States of America

Brucellosis is a zoonotic bacterial disease that causes recurring febrile illness in humans, as well as reproductive failure and reduced milk production in livestock. The cost of brucellosis is equal to the sum of lost productivity of humans and animals, as well as private and public expenditures on brucellosis surveillance, prevention, control and treatment. In Albania, Brucella abortus and B. melitensis affect humans, cattle and small ruminants. In the United States, B. abortus affects cattle and wild ungulates in the Greater Yellowstone Area. These two case studies illustrate the importance of place-specific context in developing sustainable and effective brucellosis mitigation policies. Government regulations and mitigation strategies should be designed with consideration of all costs and benefits, both to public agencies and private stakeholders. Policy-makers should, for example, weigh the benefits of a regulation that increases epidemiological certainty against the costs of compliance for producers and households. The distribution of costs and benefits amongst public agencies and private individuals can have important implications for a policy's economic efficiency and equity quite apart from their total magnitude.

Systematic review of brucellosis in Kenya: disease frequency in humans and animals and risk factors for human infection

BACKGROUND

Brucellosis is a debilitating zoonotic disease affecting humans and animals. A comprehensive, evidence-based assessment of literature and officially available data on animal and human brucellosis for Kenya are missing. The aim of the current review is to provide frequency estimates of brucellosis in humans, animals and risk factors for human infection, and help to understand the current situation in Kenya.

METHODS

A total of accessible 36 national and international publications on brucellosis from 1916 to 2016 were reviewed to estimate the frequency of brucellosis in humans and animals, and strength of associations between potential risk factors and seropositivity in humans in Kenya.

RESULTS

The conducted studies revealed only few and fragmented evidence of the disease spatial and temporal distribution in an epidemiological context. Bacteriological evidence revealed the presence of Brucella (B.) abortus and B. melitensis in cattle and human patients, whilst B. suis was isolated from wild rodents only. Similar evidence for Brucella spp infection in small ruminants and other animal species is unavailable. The early and most recent serological studies revealed that animal brucellosis is widespread in all animal production systems. The animal infection pressure in these systems has remained strong due to mixing of large numbers of animals from different geographical regions, movement of livestock in search of pasture, communal sharing of grazing land, and the concentration of animals around water points. Human cases are more likely seen in groups occupationally or domestically exposed to livestock or practicing risky social-cultural activities such as consumption of raw blood and dairy products, and slaughtering of animals within the homesteads. Many brucellosis patients are misdiagnosed and probably mistreated due to lack of reliable laboratory diagnostic support resulting to adverse health outcomes of the patients and routine disease underreporting. We found no studies of disease incidence estimates or disease control efforts.

CONCLUSION

The risk for re-emergence and transmission of brucellosis is evident as a result of the co-existence of animal husbandry activities and social-cultural activities that promote brucellosis transmission. Well-designed countrywide, evidence-based, and multidisciplinary studies of brucellosis at the human/livestock/wildlife interface are needed. These could help to generate reliable frequency and potential impact estimates, to identify Brucella reservoirs, and to propose control strategies of proven efficacy.

[The effects of repetitive extragenic palindromic sequences from Brucella melitensis DNA on the toll-like receptor 9-mediated interferon-α production]

OBJECTIVE

To screen the repetitive extragenic palindromic sequences with activation of toll-like receptor 9 (TLR9) activity from Brucella melitensis DNA, providing new ideas and new targets for prevention and treatment of brucellosis.

METHODS

Bioinformatics methods were used to detect repetitive extragenic palindromic (REP) sequences from Brucella melitensis DNA. The studied REPs were selected and synthesized. RAW264.7 was cultured and transfected with REPs mediated by lipofectamine 3000. Additionally, TLR9-siRNA was used to downregulate TLR9 expression. The content of interferon-α (IFN-α) in the supernatant was then measured by ELISA.

RESULTS

A total of 2 200 REP sequences in Brucella melitensis DNA were identified. Twelve REP sequences were synthesized for further detecting of the TLR9 agonistic activity. IFN-α expression in RAW264.7 treated with M2, M3, M4, M5, M6, M7, M9, M12 were (26.944 ± 1.868), (46.461 ± 2.562), (34.980 ± 2.055), (43.016 ± 2.162), (62.533 ± 4.031), (67.125 ± 5.069), (18.908 ± 1.633), (39.572 ± 2.465) pg/ml respectively, which significantly increased when compared with the negative control group [(12.594 ± 1.338) pg/ml, t=10.817, 20.295, 15.812, 20.724, 20.365, 18.016, 5.180, 16.660, all P<0.05]. Additionally, TLR9-siRNA can significantly decrease the levels of IFN-α in RAW264.7 treated with M6.

CONCLUSION

REP sequences presented in Brucella melitensis DNA are able to induce IFN-α expression through TLR9, which can be helpful for the understanding of pathogenesis and immunity of Brucella melitensis.

Hospital-associated transmission of Brucella melitensis outside the laboratory

Brucella melitensis was identified in an aspirate obtained from a patient's hip joint during a procedure at a hospital in Canada. We conducted an investigation into possible exposures among hospital workers; 1 worker who assisted with the procedure tested positive for B. melitensis. Aerosol-generating procedures performed outside the laboratory may facilitate transmission of this bacterium.

First case report of brucellosis in a child in Thailand

Brucellosis is uncommon in children. In Thailand, there have been only seven adult cases reported, all with Brucella melitensis. We describe here the first reported pediatric case of brucellosis in Thailand. A 12-year old boy presented with prolonged fever for one month, pancytopenia, pneumonia and peritonitis. The blood culture grew out Brucella melitensis. He responded well to combination therapy consisting of doxycycline and gentamicin. He recovered fully without relapse during the 6 month follow-up.

Brucellosis with pulmonary involvement in a premature infant

Congenital brucellosis is rare. A premature infant with transplacentally acquired congenital brucellosis and pulmonary involvement is described.

Epidemiology of brucellosis in domestic animals caused by Brucella melitensis, Brucella suis and Brucella abortus

Brucellosis is a disease that causes severe economic losses for livestock farms worldwide. Brucella melitensis, B. abortus and B. suis, which are transmitted between animals both vertically and horizontally, cause abortion and infertility in their primary natural hosts - goats and sheep (B. melitensis), cows (B. abortus) and sows (B. suis). Brucella spp. infect not only their preferred hosts but also other domestic and wild animal species, which in turn can act as reservoirs of the disease for other animal species and humans. Brucellosis is therefore considered to be a major zoonosis transmitted by direct contact with animals and/or their secretions, or by consuming milk and dairy products.

Misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®: a case report

OBJECTIVE

To describe the misidentification of Brucella melitensis as Bergeyella zoohelcum by MicroScan WalkAway®, a commonly used bacterial identification system.

CLINICAL PRESENTATION AND INTERVENTION

A 35-year-old man was admitted to the Intensive Care Unit with sepsis syndrome. Three sets of aerobic blood culture samples were positive after 48 h of incubation. The isolated organism was identified as B. zoohelcum using the MicroScan WalkAway (Siemens Healthcare Diagnostics Inc., West Sacramento, Calif., USA). However, due to the rareness of the pathogen, the isolate was reidentified as B. melitensis with Vitek® 2 system and later 16S ribosomal sequence analysis confirmed the isolate as B. melitensis having 100% match.

CONCLUSION

This case showed that Brucella can be misidentified using MicroScan WalkAway. Countries where brucellosis is endemic need to be careful while using such automated identification systems in order not to miss the diagnosis of Brucella.

Epidemiological characteristics of brucellosis in sheep and goats in Bulgaria: 2005-2008

AIM

To analyse and present the epidemiological and epizootological situation of brucellosis in humans, sheep and goats caused by Brucella melitensis.

METHODS

The veterinary health services analyzsd epidemiological reports, as well as other official documents, in relation to the epidemiology and the measures undertaken for control of brucellosis in Bulgaria, 2005-08.

RESULTS

In Bulgaria animal infections caused by Brucella melitensis have been eradicated since 1941. In 2005 several Bulgarian citizens with Brucella infection were diagnosed in the National Reference Laboratory. All the cases were imported, mostly by employees on sheep and goat farms in Greece. For a period of four years, the number of infected humans was 120 and distributed in 12 districts. Epidemiological investigations suggested that 45 persons (37.5%) were infected in Greece and 4 in Cyprus, Turkey, Italy and Tanzania respectively. All other patients were considered to be infected in Bulgaria. They were owners of infected sheep and goats or consumers of contaminated dairy products with Brucella melitensis. In June 2006, the first outbreaks of brucellosis in sheep and goat farms were recorded in the Smolyan district. By the end of 2008, the infection was registered in 16 villages of 4 districts. The average prevalence rate in the infected herds was 12.2% in goats and 1.8% in sheep. In order to achieve eradication 496 goats and 117 sheep were slaughtered.

CONCLUSION

A farm where goats from Greece were introduced illegally in 2005 was identified as the primary source of the infection. the negative epidemiological aspects of free movement of goods and persons in the European Union are considered.

Control and eradication strategies for brucella melitensis infection in sheep and goats

AIM

To describe the various strategies for the control and eradication of B. melitensis infection in sheep and goats.

METHODS

The advantages and drawbacks of these strategies are discussed on the basis of the author's personal experience and a revision of the relevant literature.

RESULTS

Vaccination programmes in various combinations can be applied either to decrease the prevalence of infection in the animal population or, when combined with adequate complementary eradication measures, to achieve a brucellosis-free status.

CONCLUSION

Controlling the disease should be the primary goal of the veterinary services involved. However, eradication should be the final objective of any control programme implemented. The selection of an eradication or control strategy is of paramount relevance, and a frequent cause of controversy among decision-makers. The final strategy should be established according to the quality of the veterinary services organisation, the economic resources available and the extent and prevalence of disease. Cooperation with farmers is essential to succeed with the application of even the most elementary control programme. When brucellosis is highly prevalent, mass (whole-flock) vaccination is the choice to control the disease, independently of the socioeconomic situation. Once effective control of the disease has been accomplished, its eradication is feasible. For successful eradication, the adequate quality and organisation of veterinary services, the strict control of animal movements and the provision of adequate economic compensation to affected farmers are compulsory. When the disease is fully eradicated, a surveillance strategy has to be implemented for the early detection of eventual new outbreaks or disease reintroduction.

Insights into the problem of B. Melitensis and rationalizing a vaccination programme in Israel

AIM

To present the problem of brucellosis caused by B. melitensis in Israel and to develop a rationalized control programme and eradication campaign in small ruminants.

METHODS

CFT, an OIE prescribed test and a confirmatory method, was used as a confirmatory test in support of legislation to compensate the farmers following a stamping-out policy. Positive reactors were cultured for Brucella spp. in order to establish epidemiological data. Vaccination using Rev. 1 Elberg vaccine strain, passage 101, 1970, has been implemented as an ocular method since November 1997.

RESULTS

Brucellosis due to B. abortus in cattle has been eradicated in Israel in beef cattle and in dairy cattle since 1984 and 1985, respectively. B. melitensis has emerged in small ruminants since 1970 and become endemic in the country. An eradication campaign has been carried out since 1993, as an interim programme between 1993 to 1995 and as a full programme up to 1997. The vaccination of pregnant animals has led to abortions and, as a result, this policy was abandoned. To date, only young replacement females are vaccinated.

CONCLUSION

Following a national eradication campaign the number of human cases declined significantly but ceasing the campaign has led to re-emergence of the disease. Cattle brucellosis due to B. melitensis has been successfully controlled with limited sporadic emerging events that have occurred since this campaign. A test and slaughter programme that is integrated with due vaccination of young replacement animals is proposed to facilitate control of the disease with the intention of achieving complete eradication.

Evaluation of the Fluorescence Polarization Assay (FPA) for diagnosis of brucella melitensis infection of goats in Argentina

AIM

Determine the optimal cut-off and the use of Fluorescence Polarization Assay (FPA) to improve the detection of brucellosis in individual goats in Argentina.

METHODS

Sera from 96 goats from a flock with abortion due to B. melitensis biovar 1 were used to assess the efficacy of the FPA to detect brucellosis in goats. FPA results were compared with those of the Buffered Antigen Plate Agglutination test (BPAT) confirmed by Seroagglutination in tube (SAT), the competitive enzyme-linked immunosorbent assay (c-ELISA) and the indirect enzyme-linked immunosorbent assay (i-ELISA). Sera from 554 goats free from brucellosis were tested with the BPAT, SAT, c-ELISA and i-ELISA to determine its Specificity. Vaccination had not been performed in the flocks evaluated.

RESULTS

The most appropriate cut-off was selected for the FPA by using MedCalc software. It was fixed at 87 mP giving a sensitivity and specificity of 98.1% (CI 89.9-99.7) and 92.8% (CI 90.4-94.7). The relative sensitivity compared with i-ELISA and c-ELISA was 97% and 92.9% respectively. The relative specificity compared with i-ELISA and c-ELISA was 97.5% and 98% respectively. The kappa measures of agreement between tests was higher than 0.75 CONCLUSION: The high correlation between FPA results and other serological methods with sera goats is indicative of the excellent performance of FPA technique in diagnosis of caprine brucellosis and we endorse it as a recommended method.

[Renal cyst infected by Brucella]

OBJECTIVES

To report one case of renal cyst infected by Brucella, an exceptional pathology in our environment.

METHODS

82-year-old patient who was referred from his primary care physician for persistent microhematuria and piuria without evidence of infection.

RESULTS

Radiological studies (XR+US+CTscan) showed a left renal cyst with parietal calcifications. Pathologic study was compatible with complicated cyst, with cultured (+) to Brucella spp.

CONCLUSIONS

Renal involvement by Brucella is exceptional, and the cystic renal involvement is by far one of the more exceptional manifestations.

[Brucellosis spondilitis in a ten year boy]

INTRODUCTION

Brucellosis is acute infectious disease classified as zoonosis, which can leave humans with chronic damages and disability. It can appear as sporadic cases or a smaller epidemic anywhere in the world but it is more common in some areas and there it presents significant public health issue. Clinical picture is very variegated. A long period of latency is possible, unnoticed asymptomatic start or forms with mild clinical picture up to the forms with per acute septic-toxic shock and possible lethal outcome. Symptoms of general infectious syndrome, wave like (undulating) temperature, profuse night sweat, muscle, bone and joint pain can be considered to be characteristic. Diagnosis is made based on epidemiological data, clinical findings, microbiological and serological tests. Differentially diagnostic all long-lasting febrile diseases may be considered and disease with neuralgic and arthralgic syndromes. Therapy includes antibiotics and prevention implies sanitary veterinary control, food control and measures of professional protection.

METHODS

This paper descriptively describes clinical course of the disease in ten year old boy with brucellosis spondylitis.

CASE REPORT

Ten year old boy was hospitalized for febrile condition and acute pain in back and abdomen of unknown etiology. We did diagnostic and therapeutic treatment with multidisciplinary approach and due to information on previous cases of brucellosis in family we also added tests to brucellosis. Diagnosis of brucellosis spondylitis is made based on MRI of lumbosacral spine and is confirmed with positive serological tests and positive blood cultures to Brucella melitensis. The boy had no other localized foci of the disease in other organs or systems. Etiological treatment was done in accordance to recommended antimicrobic scheme. A complete recovery was achieved with further need for observation of condition and Elisa titer to this agent.

CONCLUSION

Osteoarticular form of brucellosis is relatively common focal form of the disease in adult patients but not so common in children. Syndrome of acute lumbosacral pain in children is of unknown etiology and diagnostic procedures must include infectious diseases with possible osteo-articular symptoms including brucellosis.

Valve replacement for Brucella endocarditis: two case reports

We report two cases of successful treatment of Brucella endocarditis. Both of them were treated with antibiotics and aortic valve replacement after Brucellosis was diagnosed. In one of these cases emergency operation was required. Our observations suggest that a combined surgical and medical treatment is the best option for the management of this disease. B. endocarditis should be operated after improvement of clinical status but emergency cardiac surgery may be required if heart failure develops.