Brucella Infection Research Articles

Brucella canis and Chlamydia spp.: insights into canine infections, diagnostics, and potential tick-borne transmission

Brucella and Chlamydia spp. are zoonotic pathogens with significant implications for both human and animal health. Brucella species, which is responsible for brucellosis, manifest in a range of clinical symptoms and present substantial zoonotic risks. Though less commonly reported, canine infections with Brucella raise concerns about the potential for transmission to humans and highlight the need for continued vigilance in veterinary settings. Chlamydia spp. is notable for its ability to cause diverse diseases in animals, from mild infections to severe systemic illnesses. In dogs, Chlamydia infections can lead to symptoms such as conjunctivitis, respiratory disorders, and reproductive issues, including infertility and abortion. The zoonotic potential of Chlamydia, particularly Chlamydia felis, emphasises the need for thorough monitoring and control measures in both domestic animals and humans. Ticks play a significant role in the transmission of these pathogens. Research has identified Chlamydia spp. in ticks; however, the exact epidemiological implications remain unclear. Similarly, Brucella has been detected in ticks, but conclusive evidence of tick-borne transmission to humans or between animals is still lacking. Improved diagnostic tools and control strategies are essential for managing the risks associated with Brucella and Chlamydia infections in both animals and humans, with a particular focus on the role of ticks as potential vectors.

Upregulation of TREM2 expression in M2 macrophages promotes Brucella abortus chronic infection.

Brucella abortus (B.abortus) is a zoonotic bacterial pathogen that causes chronic host infections. The eradication of brucellosis using antibiotic therapy is often incomplete or slow. In a mouse model, the predominance of alternatively activated macrophages (also known as M2) plays an essential role in sustaining chronic infection. The underlying functional mechanism by which M2 sustains chronic infection remains unclear. Here, we show that B. abortus can enter M2 via triggering receptor expressed on myeloid cells 2 (TREM2) and promotes the upregulation of TREM2 expression of M2 in a type IV secretion system (T4SS)-dependent manner. Increased TREM2 enhances B. abortus growth within M2 by suppressing intracellular ROS production, preventing M2 pyroptosis via suppression of mitochondrial ROS (mROS), and promoting M2 proliferation by increasing β-catenin expression. In line with these results, downregulation of TREM2 expression suppressed B. abortus intracellular growth and M2 proliferation and induced M2 pyroptosis. In our mouse model, upregulation of TREM2 expression sustained the accumulation of M2 and B. abortus chronic infection, whereas downregulation of TREM2 expression restricted M2 proliferation and chronic infection. Collectively, our results suggest that targeting TREM2 may be a potential adjunct to antibiotic therapy for the prevention of chronic Brucella infection.

Long-term efficacy of oblique lateral interbody fusion combined with vertebral screw fixation for the treatment of lumbar specific infection

To explore medium and long term efficacy of oblique lateral interbody fusion (OLIF) in treating lumbar specific infection. From October 2017 to January 2021, 24 patients with lumbar specific infection were treated by OLIF combined with vertebral screw internal fixation, including 15 males and 9 females, aged from 27 to 61 years old with an average of (43.0±15.0) years old;the courses of disease ranged from 6 to 24 months with an average of (14.0±7.0) months;7 patients with L2-L3, 12 patients with L3-L4 and 5 patients with L4-L5;19 patients with tuberculosis infection and 5 patients with brucella infection. The amount of intraoperative blood loss, operative time and complications were recorded, and erythrocyte sedimentation rate(ESR), C-reactive protein (CRP), visual analogue scale (VAS), Japanese Orthopaedic Association(JOA) score and American Spinal Injury Association (ASIA) rating were compared before and one month after opertaion. All patients were followed up from 9 to 24 months with an average of (13.0±6.0) months. Operative time was (132.5±21.4) min, and intraoperative blood loss was (227.3±43.1) ml. ESR and CRP were decreased from (82.34±18.62) mmol·h-1 and (53.08±21.84) mg·L-1 before operation to (33.52±17.31) mmol·h-1 and (15.48±8.36) mg·L-1 at one month after operation, respectively (P<0.05). VAS was decreased from (7.52±1.36) before opertaion to (1.74±0.87) at one month after operation (P<0.05). JOA was increased from (17.86±3.95) before operation to (24.72±3.19) at one month after operation (P<0.05). Four patients had neurological symptoms before operation, and were classified to grade D according to ASIA classification, who were recovered to grade E at 1 month after operation. One patient was suffered from psoas major muscle injury after operation, and returned to normal at 3 weeks. One patient was suffered from abdominal distension and difficulty in defecation, and relieved after gastrointestinal decompression and enema. No complications such as abdominal organ injury and poor wound healing occurred in all patients. OLIF combined with vertebral screw internal fixation is a new minimally invasive surgical method for the treatment of lumbar specific infection, especially the lesion located on the middle lumbar vertebra. It has advantages of less trauma, short operation time, less blood loss, convenient operation, complete removal of the lesion, safety and effectiveness, and has good medium-and long-term efficacy for lumbar specific infection.

Potential Piperolactam A Isolated From Piper betle as Natural Inhibitors of Brucella Species Aminoacyl-tRNA Synthetase for Livestock Infections: In Silico Approach.

Brucellosis is an important global zoonosis caused by the bacterium Brucella sp. Brucellosis causes abortions, reproductive failure and reduced milk production, resulting in significant economic losses. Brucella species are reported to be resistant to antibiotics, which makes treatment difficult. The urgency of discovering new drug candidates to combat Brucella's infection necessitates the exploration of novel alternative agents with unique protein targets. Aminoacyl-tRNA synthetases (aaRSs), which have fundamental functions in translation, inhibit this process, stop protein synthesis and ultimately inhibit bacterial growth. The purpose of this study was to isolate piperolactam A compounds from the methanol extract of Piper betle leaves that have potential as antibacterials to inhibit the growth of Brucella sp. causing brucellosis in livestock and to analyse the mechanism of inhibitory activity of piperolactam A compounds against the aaRS enzyme through a molecular docking approach in silico. Piperolactam A was isolated from P. betle by column chromatography and characterized by UV, IR, 1D and 2D NMRs and MS, then tested for their inhibition mechanism against the enzymes threonyl-tRNA synthetase, leucyl-tRNA synthetase (LeuRS) and methionyl-tRNA synthetase in silico. The result in silico test is that piperolactam A has the potential to inhibit LeuRS enzyme with the greater binding affinity.

The research trend on neurobrucellosis over the past 30 years (1993-2023): a bibliometric and visualization analysis.

Brucellosis is a zoonotic disease caused by Brucella infection, which is common in pastoral areas. Neurological involvement in brucellosis is relatively rare. But since 1993, continuous studies have been reporting neurological complications of brucellosis, collectively referred to as neurobrucellosis. A bibliometric analysis of existing literature outlines current research progress and gaps and provides guidance for the clinical treatment of neurobrucellosis, promoting patient health in the process of guiding clinical practice, and improving their quality of life. CiteSpace and VOSviewer are software tools to visualize research trends and networks. By selecting specific areas of interest and configuring the right parameters, the tools can visualize past research data. The study retrieved the literature from the Web of Science Core Collection Database and downloaded it in plain text file format. Citespace6.1.6, VOSviewer v1.6.20, and Microsoft Excel 16.59 were used for analyzing the following terms: countries, institutions, authors' cooperation, journals, keywords, and co-citation. There are eight key results. (1) The publication volume shows a general upward trend. (2) Turkey is the country with the highest publication volume and contributing institutions. (3) Giambartolomei GH, Gul HC, and Namiduru M are the authors with the highest number of publications. (4) Neurology is the journal that published the highest number of related articles (n = 12). (5) "Diagnosis," "meningitis," and "features" are the top three frequently occurring keywords. (6) Keyword clusters show "antibiotic therapy" and "cerebrospinal fluid" have future study value. (7) The burst analysis of the keywords also indicates that "cerebrospinal fluid" may become a prominent keyword in future research. (8) The co-citation analysis concludes three categories of the cited articles, which are diagnosis, therapy, and complications, indicating the past research direction. This study highlights the complexity of neurobrucellosis, presenting the need for advanced diagnostic techniques and multifaceted treatment approaches. While antibiotics remain the cornerstone of therapy, the use of corticosteroids to mitigate inflammatory responses shows promise, albeit with concerns about potential sequelae and relapse. Future research should focus on refining therapeutic strategies that address both the direct effects of infection and the broader immunological impacts to improve patient outcomes and quality of life.

Hypertonic Saline Induces Host Protective Immune Responses against Brucella abortus Infection in Mice.

Hypertonic saline (HTS) resuscitation can enhance immune responses against various pathogens, however, the effect of HTS on brucellosis is yet to be defined. In this study, we found that HTS inhibited Brucella infection in mice by augmenting Th1 immunity. HTS treatment enhanced the serum cytokines production and the expression of nitric oxide synthase (NOS2) and nuclear factor kappa B (NF-ĸB) p50 and p65, crucial anti-Brucella effectors in splenocytes. In addition, HTS treatment also inhibited the phosphorylation of MAPK signaling, accompanied by the down-regulation of the autophagy marker LC3B-II. Due to directing an appropriate immune response, HTS treatment substantially decreased bacterial burden in spleen and liver tissues. In summary, corroborating previous studies showing the antimicrobial effects of HTS, our findings indicate that HTS treatment triggers a protective immune response against Brucella infection. Additionally, these results provide promising evidence of the immunomodulatory role of HTS in controlling bacterial infections.

Case Report : Brucella infection of total knee arthroplasty - The first case report in an endemic country!

Prosthetic joint loosening due to Brucella spp. is a rare event. In this report, we describe a rare case of prosthetic infection caused by brucella. A 71-year-old woman reported a six-month history of progressing pain in the right prosthetic knee, which had been implanted for arthrosis four years prior to admission, associated with fever. No night sweats were noted. On examination, the right knee appeared slightly swollen and painful on mobilization, and the surgical wound was normal. Blood tests showed increased C-Reactive Protein (CRP) (34mg/L) and erythrocyte sedimentation rate (ESR) (34mm/hr). A CT scan of her right knee was performed, showing loosening of the prosthesis, joint effusion, and osteolysis in contact with the internal tibial component measuring 16mm maximum with bone remodeling of the epiphysis and metaphysis regions. Rose Bengal test was positive for brucellosis, a standard brucella tube agglutination test was positive at a titer of 1/80, blood cultures for brucella were negative and a PCR for detection of Mycobacterium tuberculosis was negative. The patient was diagnosed as having Brucella infection of his total knee arthroplasty. Favorable outcome was observed after medical and surgical treatment. We believe this is the first detailed report of Brucella prosthetic infection in the country despite the endemicity of this type of zoonosis.

Study of the Prevalence of Bovine Brucellosis (Brucella abortus) in General Proaño Parish: Evaluation using Rose Bengal Test and Confirmation through Competitive ELISA

Bovine brucellosis is an infectious pathology that compromises animal well-being and causes significant economic losses for livestock farmers. This disease leads to abortions and is caused by the bacterium Brucella abortus. In this research, the prevalence of bovine brucellosis (Brucella abortus) was estimated in General Proaño Parish using the Rose Bengal test and confirmation through competitive ELISA. Methodologically, The research was carried out between February and August 2023 on 100 animals from 25 locations in the Proaño parish, in the Morona canton, Ecuador. Blood serum was obtained from five breeds of cattle: Charolais, Holstein, Brown Swiss, Mestiza and Jersey. The collected samples were transported to the laboratory for their respective analysis. Five milliliters of venous blood were collected from the coccygeal vein, from which 1 mL of blood serum was obtained. The serum was used for disease diagnosis through the Rose Bengal test, and those that tested seropositive were reconfirmed using the competitive ELISA immunoassay method. The clinical analyses determined that there is a 0% prevalence of the pathology; based on these results, we can state that the null prevalence of Brucella may be due to environmental and geographical factors that influence its presence and transmission. Furthermore, the precision and sensitivity of the diagnostic methods used are crucial; however, the ELISA and Rose Bengal methods may have been insensitive and did not detect mild infections. Finally, Brucella infection may not be present during sampling due to temporal fluctuations in its prevalence. In conclusion, there is no scientific evidence of bovine brucellosis as the primary cause of abortions and gestational losses in the study area.

Design a novel of Brucellosis preventive vaccine based on IgV_CTLA-4 and multiple epitopes via immunoinformatics approach

Brucellosis is a zoonotic disease caused by Brucella, which is difficult to eliminate by conventional drugs. Therefore, a novel multi-epitope vaccine (MEV) was designed to prevent human Brucella infection. Based on the method of “reverse vaccinology”, cytotoxic T lymphocyte epitopes (CTLEs), helper T lymphocyte epitopes (HTLEs), linear B-cell epitopes (LBEs) and conformational B-cell epitopes (CBEs) of four Brucella proteins (VirB9, VirB10, Omp 19 and Omp 25) were obtained. In order to keep the correct protein folding, the multiple epitopes was constructed by connecting epitopes through linkers. In view of the significant connection between human leukocyte antigen CTLA-4 and B7 molecules found on antigen presenting cells (APCs), a new vaccine (V_C4MEV) for preventing brucellosis was created by combining CTLA-4 immunoglobulin variable region (IgV_CTLA-4) with MEV protein. Immunoinformatics analysis showed that V_C4MEV has a good secondary and tertiary structure. Additionally, molecular docking and molecular dynamics simulation (MD) revealed a robust binding affinity between IgV_ CTLA-4 and the B7 molecule. Notably, the vaccine V_C4MEV was demonstrated favorable immunogenicity and antigenicity in both in vitro and in vivo experiments. V_C4MEV had the potential to activate defensive cells and immune responses, offering a hopeful approach for developing vaccines against Brucella in the upcoming years.

Serological Investigation for Brucella ceti in Cetaceans from the Northwestern Mediterranean Sea.

Neurobrucellosis in cetaceans, caused by Brucella ceti, is a relevant cause of death in striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea. Serological tests are not used as a routinary technique for the diagnosis of this infection. We briefly describe the pathological findings of nine free-ranging stranded cetaceans diagnosed with Brucella disease or infection in our veterinary necropsy service from 2012 to 2022. The findings included focal diskospondylitis and non-suppurative meningitis, choroiditis and radiculitis. Additionally, an exploratory serological study was conducted in sixty-six frozen sera collected in the period 2012-2022 from fifty-seven striped dolphins, five Risso's dolphins (Grampus griseus), two common bottlenose dolphins (Tursiops truncatus), one common dolphin (Delphinus delphis) and one pilot whale (Globicephala melas) to compare antibody levels in Brucella-infected (n = 8) and non-infected (n = 58) animals, classified by the cause of death, sex, age class and cetacean morbillivirus (CeMV) infection status. The authors hypothesized that active infection in cases of neurobrucellosis would elicit a stronger, detectable humoral response compared to subclinical infections. We performed a commercial competition ELISA (cELISA) using serial serum dilutions for each sample, considering a percentage of inhibition (PI) of ≥40% as positive. A titer of 1:160 was arbitrarily determined as the seropositivity threshold. Seropositive species included striped dolphins and Risso's dolphins. Seroprevalence was higher in animals with neurobrucellosis (87.5%) compared to the overall seroprevalence (31.8%) and to other causes of death, indicating, likely, a high sensitivity but low specificity for neurobrucellosis. Animals with chronic CeMV seemed to have higher seroprevalences, as well as juveniles, which also had a higher disease prevalence. These results indicate, as in other studies, that antibodies are not decisive against clinical brucellosis, although they may indicate a carrier state, and that CeMV may influence Brucella epidemiology. More research is required to elucidate the epidemiology and pathogenesis and to resolve the complicated host-pathogen interaction in Brucella species.

Pathogenesis of Brucella suis biovar 1 in the armadillo (Chaetophractus villosus).

Brucella suis biovar 1 has the broadest animal host spectrum. Affects domestic animals and wildlife species. The aim of our study was to investigate the pathogenesis of B. suis biovar 1 infection in the armadillo (Chaetophractus villosus) under experimental conditions. One gravid female and three adult males were inoculated with a suspension containing 1×106 CFU/mL (colony-forming units) of B. suis biovar 1 by oral route. In addition, the gravid female and one male received the same suspension by the conjunctival route. A young male and two females not inoculated were kept in contact with the animals inoculated. The animals that tested seropositive were euthanized. All inoculated armadillos showed positive antibody titres 2 weeks post-inoculation. Of the three uninoculated animals, one female was seropositive for Brucella infection. Brucella was isolated from the spleen, liver, mesenteric lymph nodes, uterus, testes, and urine. Characteristic histologic lesions were found in the epididymis. These results suggest that armadillos can act as a reservoir for the spread of B. suis infection, and the persistence of Brucella in armadillo tissues constitutes a risk for humans, because of the cultural practice of armadillo meat consumption in rural communities.

Seroprevalence of brucellosis among high-risk individuals in Madinah, Saudi Arabia.

Brucellosis is a highly contagious, neglected zoonotic disease of major importance worldwide. The disease is endemic in many countries, burdening healthcare systems and the livestock industry and representing a persistent public health concern in these countries. Brucellosis is considered an important occupational hazard for livestock workers. Limited studies have investigated human brucellosis in Saudi Arabia. Therefore, this study aimed to estimate the prevalence of brucellosis among employees of high-risk brucellosis professions, including veterinarians, animal herders, and abattoir workers in Madinah, Saudi Arabia, and to determine the associated risk factors. A cross-sectional study was conducted in Madinah, Saudi Arabia, during the period of January-March 2023. Ninety blood samples were collected from individuals occupationally at risk of exposure to Brucella infections. Serum samples were examined for immunoglobulins (Ig)M and IgG antibodies against Brucella using an indirect enzyme-linked immunosorbent assay. Before sample collection, a predesigned online questionnaire was used to collect the participants' sociodemographic characteristics and the probable risk factors for human brucellosis. A Chi-square test was used to compare the differences among groups; p < 0.05 were considered statistically significant. Among the 90 participants among the high-risk individuals, Brucella IgM and IgG seropositivity were found in 8 (8.8%) and 11 (12.12%) cases, respectively. IgM mono antibody positivity was observed in 4 (4.44%) and 7 (7.77%) of the study population who tested positive for IgG only. Dual positivity for IgM and IgG antibodies was observed in 4 (4.44%) participants. No significant association was determined between seropositivity and age, urbanicity, education, occupation, and duration of exposure (p > 0.05). Brucellosis is a high-risk occupational disease among workers with close contact with livestock. This study demonstrates that the seroprevalence of brucellosis among occupationally high-risk individuals in Madinah, Saudi Arabia, is relatively low compared to other countries in the region. Nevertheless, educational programs should be implemented to improve knowledge regarding brucellosis, particularly among high-risk individuals.

Single-cell landscape revealed immune characteristics associated with disease phases in brucellosis patients.

A comprehensive immune landscape for Brucella infection is crucial for developing new treatments for brucellosis. Here, we utilized single-cell RNA sequencing (scRNA-seq) of 290,369 cells from 35 individuals, including 29 brucellosis patients from acute (n = 10), sub-acute (n = 9), and chronic (n = 10) phases as well as six healthy donors. Enzyme-linked immunosorbent assays were applied for validation within this cohort. Brucella infection caused a significant change in the composition of peripheral immune cells and inflammation was a key feature of brucellosis. Acute patients are characterized by potential cytokine storms resulting from systemic upregulation of S100A8/A9, primarily due to classical monocytes. Cytokine storm may be mediated by activating S100A8/A9-TLR4-MyD88 signaling pathway. Moreover, monocytic myeloid-derived suppressor cells were the probable contributors to immune paralysis in acute patients. Chronic patients are characterized by a dysregulated Th1 response, marked by reduced expression of IFN-γ and Th1 signatures as well as a high exhausted state. Additionally, Brucella infection can suppress apoptosis in myeloid cells (e.g., mDCs, classical monocytes), inhibit antigen presentation in professional antigen-presenting cells (APCs; e.g., mDC) and nonprofessional APCs (e.g., monocytes), and induce exhaustion in CD8+ T/NK cells, potentially resulting in the establishment of chronic infection. Overall, our study systemically deciphered the coordinated immune responses of Brucella at different phases of the infection, which facilitated a full understanding of the immunopathogenesis of brucellosis and may aid the development of new effective therapeutic strategies, especially for those with chronic infection.

Seroprevalence of Brucella among Patients Visiting a Single-Center Hospital: A Cross-Sectional Study

Introduction: Brucellosis is a disease that can be contracted by humans through contact with infected animals or animal products. It can be transmitted through contaminated dairy products, so caution must be exercised when handling and preparing food. By taking precautions, the spread of this disease can be mitigated to protect both humans and animals. (1) Brucella spp is a type of bacteria that can cause an infection. The symptoms of this infection can range from mild flu-like symptoms to severe complications that affect different parts of the body. Because Brucella is able to invade the body and avoid the immune system, it's important to get an accurate diagnosis and start treatment as soon as possible. (2). (3)  Method: The study was conducted at Kalkaal Hospital from 2019 to 2023, spanning three years. Patients who went to the hospital's Outpatient department and were screened for Brucella were included in the study. Data on patients' demographics, including their residence, gender, age, and Brucella screening results, were collected and recorded over the study period. The participants' blood samples were gathered and analyzed for Brucella infection through a variety of diagnostic The clinical assessment included an examination of symptoms, medical history, and possible exposure to Brucella. To detect specific antibodies (IgM and IgG) against Brucella present in the blood serum, serological tests such as the Serum Agglutination Test (SAT), ELISA, and Rose Bengal Test were conducted. The blood samples were analyzed to identify the Brucella bacteria through blood cultures. In addition, the presence of Brucella DNA was confirmed in various clinical samples using Polymerase Chain Reaction (PCR). The Kalkaal Hospital Research Review Board gave approval for the study protocol. Data cleaning was carried out with the help of Excel. The analysis of data was performed using SPSS software version 25.  Results: According to the analysis of the data, 30.3% of patients were men, and 69.7% of patients were women. The age ranges were 0–19: 1245 (8.1%), 20–29: 3951 (25.7%), 30-39: 3027 (19.7%), 40–49: 1786 (11.6%), and 50+: 4582. (29.9 percent). In addition, 14884 (97.0%) of the outcomes were negative, while only 465 (3.0%) were positive.  Conclusion: The research carried out at Kalkaal Hospital in Mogadishu, Somalia, has revealed important information about the prevalence of Brucella infection in the area. The results suggest that a significant number of patients have tested positive for Brucella antibodies, which indicates that the disease is a significant burden on the local population. These findings add to the global knowledge of brucellosis and emphasize its severe and long-term effects. It is important for experts in this field to have further discussions and come to a consensus on how to address this issue.

Revealing metabolic alterations in brucellosis patients by targeted metabolomics

Brucellosis, a zoonotic disease caused by brucella infection, presents metabolic profile changes in patients that have not been extensively explored. This study utilized an ultra-high performance liquid chromatography tandem mass spectrometry based targeted metabolomic approach to comprehensively investigated metabolic changes in Brucella patients. Serum samples of brucellosis 50 patients and 50 well-matched healthy controls were analyzed for 228 metabolites, revealing significant alterations in 83 metabolites in brucellosis patients. Notably, disruptions were observed in key metabolite pathways, such as amino acid metabolism, urea cycle, tricarboxylic acid cycle (TCA), and fatty acid metabolism. Patients diagnosed with Brucellosis exhibited distinct differences in the levels of aspartate, glutamate, β-alanine, and asparagine when compared to controls. Within the urea cycle, a significant downregulation of arginine was observed, whereas ornithine levels were considerably upregulated. In the TCA cycle, concentrations of 2-oxoglutarate, succinate, and malate were significantly elevated, while citrate levels demonstrated a notable decrease. Due to the interruption of the TCA cycle, glycolysis was accelerated to compensate for the resultant energy deficit in Brucella patients. Concurrently, there was a significant increase in the levels of short and medium-chain fatty acids, while long-chain fatty acids showed a marked decrease. The study systematically revealed significant metabolic alterations in Brucellosis patients and further explored the potential correlation between these changes and clinic symptoms, including fatigue, muscle soreness and prolonged fever. The results enhanced our understanding of Brucellosis, offering valuable insights potentially beneficial in formulating more effective treatment strategies and improving prognostic approaches.

Intranasal and intraperitoneal immunization against Brucella infection using niosome and mannosylated niosomes containing Brucella recombinant trigger factor/Bp26/Omp31 chimeric protein in a mouse model.

Brucellosis, a zoonotic infectious disease, is a worldwide health issue affecting animals and humans. No effective human vaccine and the complications caused by the use of animal vaccines are among the factors that have prevented the eradication of the disease worldwide. However, bio-engineering technologies have paved the way for designing new targeted and highly efficacious vaccines. In this regard, the study aimed to evaluate immunity induced by mannosylated niosome containing Brucella recombinant trigger factor/Bp26/Omp31 (rTBO) chimeric protein in a mouse model. rTBO as chimeric antigen (Ag) was expressed in Escherichia coli BL21 (DE3) and, after purification, loaded on niosome and mannosylated niosome. The characteristics of the nanoparticles were assessed. The mice were immunized using rTBO, niosome, and mannosylated niosome-rTBO in intranasal and intraperitoneal routes. Serum antibodies (immunoglobulin [Ig]A, IgG, IgG1, and IgG2a) and splenocyte cytokines (interferon-gamma, interleukin [IL]-4, and IL-12) were evaluated in immunized mice. Finally, immunized mice were challenged by B. melitensis and B. abortus. A high antibody level was produced by niosomal antigen (Nio-Ag) and mannosylated noisomal antigen (Nio-Man-Ag) compared to the control after 10, 24, and 38 days of immunization. The IgG2a/IgG1 titer ratio for Nio-Man-Ag was 1.2 and 1.1 in intraperitoneal and intranasal methods and lower than one in free Ag and Nio-Ag. Cytokine production was significantly higher in the immunized animal with Ag-loaded nanoparticles than in the negative control group (p<0.05). Moreover, cytokine and antibody levels were significantly higher in the injection than in the inhalation method (p<0.05). The combination of mannosylated noisome and rTBO chimeric proteins stimulate the cellular and humoral immune response and produce cytokines, playing a role in developing the protective acquired immune response in the Brucella infectious model. Also, the intraperitoneal route resulted in a successful enhancement of cytokines production more than intranasal administration. Designing an effective vaccine candidate against Brucella that selectively induces cellular and humoral immune response can be done by selecting a suitable nanoniosome formulation as an immunoadjuvant and recombinant protein as an immune response-stimulating Ag.

Human brucellosis and associated risk factors in the Middle East region: A comprehensive systematic review, meta-analysis, and meta-regression

IntroductionHuman brucellosis, caused by the bacteria Brucella, is a significant infectious disease globally, also known as Mediterranean fever or Malta fever. MethodsThis meta-analysis and systematic review focuses on the prevalence rate, risk factors, and diagnostic methods of human brucellosis in Middle Eastern countries, where the disease remains a significant public health issue. The analysis included 92 studies conducted between 1993 and 2024, following specified inclusion and exclusion criteria among symptomatic patients across these countries. The prevalence rate was calculated by dividing positive samples by total samples. The I2 index and Chi-squared test assessed study heterogeneity. Significant heterogeneity occurred when I2 exceeded 50 %. ResultsThe highest prevalence rate was observed in Oman, Lebanon, and Kuwait countries, emphasizing a notable burden of Brucella infection in these regions. Risk factors associated with human brucellosis were identified, with unpasteurized dairy consumption and close animal contact being predominant. Various professions such as farmers, dairy factory workers, and agriculture workers showed higher prevalence rate. Gender analysis indicated a prevalence rate of 18.02 % (95 % CI: 11.55–25.51 %) in males and 13.61 % (95 % CI: 10.8–16.68 %) in females, with no significant difference in hospitalization rates. The prevalence rate of Brucella spp. was varied across detection methods, with immunocapture agglutination assay (Brucellacapt) showing the highest estimated prevalence rate of (44.04 %, 95 % CI: 27.71–61.04), followed by PCR (39.84 %, 95 % CI: 20.14–61.39) and culture (29.22 %, 95 % CI: 17.89–42.03). Among Brucella species, Brucella melitensis (B. melitensis) and Brucella abortus (B. abortus) were the highest prevalence rate. Although statistically insignificant, the meta-analysis also revealed an upward trend in prevalence rate from 1993 to 2024, (P value = 0.277). DiscussionThis comprehensive review emphasizes the need for tailored strategies to control brucellosis in the Middle East, highlighting the importance of timely diagnosis, public awareness, and effective treatment protocols. These findings provide valuable insights for policymakers and healthcare professionals working to mitigate the impact of this disease in the region.

Investigation of the Seroprevalence of Brucella Antibodies and Characterization of Field Strains in Immunized Dairy Cows by B. abortus A19.

(1) Background: One method of eradicating brucellosis is to cull cattle that test positive for antibodies 12 months after being vaccinated with the 19-strain vaccine. Variations in immunization regimens and feeding practices may contribute to differences in the rate of persistent antibodies. We conducted this study to investigate the real positive rate of Brucella antibody in field strains of Brucella spp. after immunization over 12 months in dairy cows. This research aims to provide data to support the development of strategies for preventing, controlling, and eradicating brucellosis. (2) Method: We employed the baseline sampling method to collect samples from cows immunized with the A19 vaccine for over 12 months in Lingwu City from 2021 to 2023. Serological detection was conducted using the RBPT method. An established PCR method that could distinguish between 19 and non-19 strains of Brucella was utilized to investigate the field strains of Brucella on 10 dairy farms based on six samples mixed into one using the Mathematical Expectation strategy. (3) Results: We analyzed the rates of individual seropositivity and herd seropositive rates in dairy cattle in Lingwu City from 2021 to 2023 and revealed that antibodies induced by the Brucella abortus strain A19 vaccine persist in dairy herds for more than 12 months. We established a PCR method for identifying both Brucella A19 and non-A19 strains, resulting in the detection of 10 field strains of Brucella abortus from 1537 dairy cows. By employing a Mathematical Expectation strategy, we completed testing of 1537 samples after conducting only 306 tests, thereby reducing the workload by 80.1%. (4) Conclusions: There was a certain proportion of cows with a persistent antibody titer, but there was no evidence that all of these cattle were naturally infected with Brucella. The established PCR method for distinguishing between Brucella abortus strain 19 and non-19 strains can be specifically utilized for detecting natural Brucella infection in immunized cattle. We propose that relying solely on the detection of antibodies in cattle immunized with the A19 vaccine more than 12 months previously should not be solely relied upon as a diagnostic basis for brucellosis, and it is essential to complement this approach with PCR analysis to specifically identify field Brucella spp. Brucella abortus was the predominant strain identified in the field during this study. Detection based on the Mathematical Expectation strategy can significantly enhance detection efficiency.

#1061 Brucella infection in a patient with renal cystic disease and renal imaging changes before and after treatment: a case report

Abstract Background and Aims Brucellosis can affect nearly all systems. Genitourinary involvement is uncommon in patients with brucellosis, accounting for approximately 10% of cases. We diagnosed a rare case of renal cysts with brucellosis and reported renal imaging changes before and after treatment. Method A 38-year-old man was admitted to our hospital in September 2021 with complaints of elevated serum creatinine, proteinuria for more than 2 months, and intermittent fever for 2 weeks. In July 2020, the patient experienced fatigue, and a rash on all four extremities. He denied experiencing low back pain or joint swelling. Urine analysis revealed the following: BLD (+), Pro (+), 24-hour urine protein (24 h UP) 0.7 g; blood: Cr 11.88 mg/dL, UA 77.51 mg/dL, ALP 217 IU/L, and GGT 227 IU/L. MRI revealed multiple small punctate areas with short T1 signals in both kidneys and splenomegaly. Soon, he experienced persistent afternoon fever with a maximum temperature of 39.0°C, along with night sweats and left lumbar pain. There were no symptoms of cough, expectoration, or urinary tract irritation. The patient had diabetes mellitus and diabetic retinopathy. He has lived in the Inner Mongolia Autonomous Region. He denied having any contact with raw milk or mice. His father and sister had kidney disease and diabetes. In September 2021, the patient was admitted to our hospital. Urinalysis revealed BLD (-), Pro 0.3 g/L, and 24 hUP 1.39 g; blood: HGB 117 g/L, ALP 227 U/L, GGT 221 U/L, Cr 2.56 mg/dL, UA 88.79 mg/dL, and K 3.2 mEq/L. The infection indicators were as follows: the standard tube agglutination test (+) (Fig. 1), Brucella (+) in blood culture, a positive qualitative test for blood cryptococcal antigen and qualitative positive results for 6 Cryptococcus neoformans sequences in bronchoalveolar lavage fluid using next-generation sequencing. Ultrasound showed multiple cysts in both kidneys. It also showed uneven echogenicity in the left testis and visible lymph nodes in the left neck, bilateral axillae and groin. CT revealed cavitary nodules and ground-glass opacities in the right middle lobe, as well as splenomegaly. MRI revealed renal cysts (Fig. 2a, b, c) and abscesses (Fig. 2e, f, g). The patient was diagnosed with stage 3 chronic kidney disease (CKD), pulmonary cryptococcosis, and brucellosis associated with renal abscess, left orchitis, splenomegaly, multiple lymphadenopathies, rash, and hyperuricemia. Doxycycline, rifampicin, and fluconazole were administered. He had no fever, his low back pain had disappeared, and his rash were relieved. Results A reexamination after 2 months revealed the following: the urinalysis results revealed a BLD (-), Pro(-), and 24 hUP 0.15 g; blood: GGT 107 IU/L; ALP 72 IU/L; Cr 1.89 mg/dL; UA 0.22 mg/dL; and K 4.0 mEq/L. Ultrasound revealed a decrease in the size of the spleen. MRI revealed the liquefaction of renal abscesses. Brucella therapy has been found to be effective. Conclusion The patient was a young man who was infected with both Brucella and Cryptococcus. Although his hometown was in an area affected by an epidemic, his current residence was not affected. Namely, he was immunocompromised, which was associated with diabetes. After receiving anti-Brucella treatment, his symptoms disappeared, the renal abscess liquefied, but creatinine decreased to levels similar to those at onset without a decreasing trend. These findings suggest that the patient had underlying CKD that was not associated with Brucellosis. We believe that the CKD was diabetes and renal cysts. He had hyperuricemia, hypomagnesaemia, unexplained asymptomatic abnormal liver function, and mild proteinuria. Imaging indicated the presence of renal cysts. In addition to having diabetes, he had a family history of kidney disease and diabetes. We diagnosed the patient with CKD and as having autosomal dominant tubulointerstitial disease (ADTKD) associated with the HNF1B pathogenic gene mutation. This gene mutation is also rare in ADTKD patients. Genetic testing revealed that the causative genes include NM001303448. Potential causative genes included NM000128. The mutated genes mentioned above are not typical causative genes for HNF1B or other types of ADTKD.

Brucella Manipulates Host Cell Ferroptosis to Facilitate Its Intracellular Replication and Egress in RAW264.7 Macrophages.

Brucella virulence relies on its successful intracellular life cycle. Modulating host cell death is a strategy for Brucella to survive and replicate intracellularly. Ferroptosis is a novel regulated cell death characterized by iron-triggered excessive lipid peroxidation, which has been proven to be associated with pathogenic bacteria infection. Thus, we attempted to explore if smooth-type Brucella infection triggers host cell ferroptosis and what role it plays in Brucella infection. We assessed the effects of Brucella infection on the lactate dehydrogenase release and lipid peroxidation levels of RAW264.7 macrophages; subsequently, we determined the effect of Brucella infection on the expressions of ferroptosis defense pathways. Furthermore, we determined the role of host cell ferroptosis in the intracellular replication and egress of Brucella. The results demonstrated that Brucella M5 could induce ferroptosis of macrophages by inhibiting the GPX4-GSH axis at the late stage of infection but mitigated ferroptosis by up-regulating the GCH1-BH4 axis at the early infection stage. Moreover, elevating host cell ferroptosis decreased Brucella intracellular survival and suppressing host cell ferroptosis increased Brucella intracellular replication and egress. Collectively, Brucella may manipulate host cell ferroptosis to facilitate its intracellular replication and egress, extending our knowledge about the underlying mechanism of how Brucella completes its intracellular life cycle.