Risk Factors for Relapse of Human Brucellosis

Proteomics Exploration of Brucella melitensis to Design an Innovative Multi-Epitope mRNA Vaccine

Brucellosis is a chronic and debilitating disease in humans, causing great economic losses in the livestock industry. Making an effective vaccine is one of the most important concerns for this disease. The new mRNA vaccine technology due to its accuracy and high efficiency has given promising results in various diseases. The objective of this research was to create a novel mRNA vaccine with multiple epitopes targeting Brucella melitensis. Seventeen antigenic proteins and their appropriate epitopes were selected with immunoinformatic tools and surveyed in terms of toxicity, allergenicity, and homology. Then, their presentation and identification by MHC cells and other immune cells were checked with valid tools such as molecular docking, and a multi-epitope protein was modeled, and after optimization, mRNA was analyzed in terms of structure and stability. Ultimately, the immune system's reaction to this novel vaccine was evaluated and the results disclosed that the designed mRNA construct can be an effective and promising vaccine that requires laboratory and clinical trials.

Safe Subunit Green Vaccines Confer Robust Immunity and Protection against Mucosal Brucella Infection in Mice

Brucellosis is a zoonotic disease that causes significant negative impacts on the animal industry and affects over half a million people worldwide every year. The limited safety and efficacy of current animal brucellosis vaccines, combined with the lack of a licensed human brucellosis vaccine, have led researchers to search for new vaccine strategies to combat the disease. To this end, the present research aimed to evaluate the safety and efficacy of a green vaccine candidate that combines Brucella abortus S19 smooth lipopolysaccharide (sLPS) with Quillaja saponin (QS) or QS-Xyloglucan mix (QS-X) against mucosal brucellosis in BALB/C mice. The results of the study indicate that administering two doses of either sLPS-QS or sLPS-QS-X was safe for the animals, triggered a robust immune response, and enhanced protection following intranasal challenge with S19. Specifically, the vaccine combinations led to the secretion of IgA and IgG1 in the BALF of the immunized mice. We also found a mixed IgG1/IgG2a systemic response indicating evidence of both Th1 and Th2 activation, with a predominance of the IgG1 over the IgG2a. These candidates resulted in significant reductions in the bioburden of lung, liver, and spleen tissue compared to the PBS control group. The sLPS-QS vaccination had conferred the greatest protection, with a 130-fold reduction in Brucella burdens in lung and a 55.74-fold reduction in the spleen compared to PBS controls. Vaccination with sLPS-QS-X resulted in the highest reduction in splenic Brucella loads, with a 364.6-fold decrease in bacterial titer compared to non-vaccinated animals. The study suggests that the tested vaccine candidates are safe and effective in increasing the animals’ ability to respond to brucellosis via mucosal challenge. It also supports the use of the S19 challenge strain as a safe and cost-effective method for testing Brucella vaccine candidates under BSL-2 containment conditions.

Use of the quantum dot-labeled solid lipid nanoparticles for delivery of streptomycin and hydroxychloroquine: A new therapeutic approach for treatment of intracellular Brucella abortus infection

Brucellosis is considered one of the most important infectious diseases affecting any tissue and organ in the human body. Due to the intracellular pathogenesis of Brucella species, the use of conventional antibiotics for managing chronic brucellosis has several limitations. Therefore, the study focused on the use of solid lipid nanoparticles (SLN) to deliver streptomycin (STR) for intracellular infection, with or without the combination of hydroxychloroquine (HCQ) to evaluate if there might be a boost in the antibiotic effect when using the STR or STR-NPs alone. We used the double emulsion technique to synthesize Nano drug carriers; afterward, the physicochemical characteristics of synthesized Nano drug carriers were determined. The in vitro antibacterial activity of free drugs and Nano drug carriers were evaluated using well diffusion, broth microdilution assays (BMD), and murine macrophage-like cells cell line J774A.1. Additionally, acute and chronic phases of brucellosis were inducted into Wistar rats, and healing capacity of Nano drug carriers on liver and spleen tissues was compared with free drugs. The zeta potential of nanoparticles, means of size, Polydispersity Index (PDI), drugs loading, and encapsulation efficiency were 15.2 mV, 312.5 ± 26 nm, 0.433 ± 0.09, 16.6% and 89.5%, respectively. Well diffusion and BMD methods did not show a significantly differ between free drugs and nano drug carriers. However, the Nano drug carriers remarkably decreased the number of bacteria in the cell line compared to the free drugs. STR/HCQ-SLN enhanced the healing processes of the liver and spleen after brucellosis induction. STR/HCQ-SLN showed better inhibitory effects against the chronic phase of B. abortus infection in comparison to the STR-SLN, but this difference was not statistically significant. Using nanoplatforms to enhance conventional anti-brucellosis agents is promising, green and safe. Due to the continuous release of drugs, drugs increase their accumulation at the site of infection, causing a more significant effect on the chronic and acute phases of brucellosis.

Brucella Infectious Aneurysm: A Retrospective Study of 14 Cases and Review of the Literature - Case Report and Literature Review

Objective

To analyze the clinical characteristics and treatment process of 14 patients with aneurysm due to brucellosis, summarize the morbidity characteristics, and improve the knowledge and diagnosis of the disease.

Methods

The clinical data of patients with aneurysms who were diagnosed to have brucellosis through Rose Bengal Test (RBT), Serum Agglutination Test (SAT), blood culture, and computed tomography angiography from January 2012 to November 2022 in Bethune Hospital, Shanxi Province, China, were retrospectively analyzed, and their clinical characteristics and disease regression findings were summarized.

Results

Of the 14 patients, 13 were men, and 1 was a woman; the youngest patient was 48-year-old, and the oldest patient was of 74 years. All had a history of smoking. The sites of lesion occurrence included the abdominal aorta (5 patients), abdominal aorta +iliac artery (5 patients), iliac artery (2 patients), thoracic aorta and brachial artery were less common (1 case each). Symptoms in the patients mostly began with abdominal pain, which was accompanied by fever, nausea, and vomiting. Six patients had a clear history of livestock exposure. Fourteen patients showed elevated D-dimer and C-reactive protein levels and decreased hemoglobin and albumin levels. Thirteen of the 14 cases were treated surgically, there were no complications of surgery, and 3 patients were readmitted with recurrence of brucellosis, it is related to the treatment that did not reach the early stage, combination, full dose and full course of treatment, with a mean recurrence time of 8 months. In the telephone follow-up, the patient's recovery proceeded well.

Conclusion

The present study revealed that the recurrence in male gender, advanced age, smoking and irregular treatment is higher. On the contrast, early intervention, a combination of adequate course of anti-infection treatment and timely surgery can improve the prognosis.

Femoral Head Necrosis Due to Brucella Infection in China: Case Series and Literature Review

Introduction

The causes of femoral head necrosis mainly include trauma, corticosteroid, and alcohol, among which Brucella is highly unusual.

Patients and Methods

This paper reported three rare cases of femoral head necrosis due to Brucella, summarizing and analyzing the epidemiological history, clinical manifestations, laboratory examinations, imaging findings, individualized therapy, and biopsy results of patients with this disease. A literature review related to brucellosis and femoral head necrosis was conducted.

Results

All three patients had an epidemic history of brucellosis. They suffered from hip pain and limitation of movement for months, and femoral head necrosis was confirmed by magnetic resonance imaging (MRI). Pathological Giemsa staining or real-time polymerase chain reaction (real-time PCR) confirmed Brucella melitensis (B. melitensis) as the cause of osteonecrosis. Each patient received individualized therapy according to the degree of osteonecrosis, which was based on anti-brucellosis medications and hip puncture and irrigation decompression. They were followed up for more than two years and rehabilitated well.

Conclusion

Brucella infection should always be considered the cause of femoral head necrosis for patients with hip pain, especially for those with an epidemic history; early diagnosis and individual stepwise therapy can prevent the progression of osteonecrosis.

The perspective of antibiotic therapeutic challenges of brucellosis in the Middle East and North African (MENA) countries: Current situation and therapeutic management

Brucellosis is among the most prevalent zoonotic infections in Middle Eastern and North African (MENA) countries, critically impacting human and animal health. A comprehensive review of studies on antibiotic susceptibility and therapeutic regimes for brucellosis in ruminants and humans in the MENA region was conducted to evaluate the current therapeutic management in this region. Different scientific databases were searched for peer-reviewed original English articles published from January 1989 to February 2021. Reports from research organizations and health authorities have been taken into consideration. Brucella melitensis and Brucella abortus have been reported from the majority of MENA countries, suggesting a massive prevalence particularly of B. melitensis across these countries. Several sporadic cases of brucellosis relapse, therapeutic failure, and antibiotic resistance of animal and human isolates have been reported from the MENA region. However, several studies proved that brucellae are still in-vitro susceptible to the majority of antibiotic compounds and combinations in current recommended WHO treatment regimens, e.g. levofloxacin, tetracyclines, doxycycline, streptomycin, ciprofloxacin, chloramphenicol, gentamicin, tigecycline, and trimethoprim/sulfamethoxazole. The current review presents an overview on resistance development of brucellae and highlights the current knowledge on effective antibiotics regimens for treating human brucellosis. This article is protected by copyright. All rights reserved.

Molecular characterization and antimicrobial susceptibility testing of clinical and non-clinical Brucella melitensis and Brucella abortus isolates from Egypt

Brucellosis is a highly contagious and incapacitating disease of humans, livestock and wildlife species globally. Treatment of brucellosis in animals is not recommended, and in humans, combinations of antibiotics recommended by the World Health Organization are used. However, sporadic antimicrobial-resistant (AMR) isolates and relapse cases have been reported from different endemic regions. In the current study, molecular characterization and antibiotic susceptibility testing using the microdilution method for 35 B. abortus and B. melitensis strains isolated from humans, milk and animal were carried out. Additionally, Next-Generation-Sequencing (NGS) technology was applied to confirm Brucella at the species level and investigate AMR and pathogenicity-associated determinants. MALDI-TOF seemed to be a rapid and reliable tool for routine identification of brucellae to the genus level; however, DNA-based identification is indispensable for accurate species identification. Brucella abortus strains were isolated from two human cases and a sheep. Such infections are uncommon in Egypt. Egyptian Brucella strains are still in-vitro susceptible to doxycycline, tetracyclines, gentamicin, ciprofloxacin, levofloxacin, chloramphenicol, streptomycin, trimethoprim/sulfamethoxazole and tigecycline. Probable (no CLSI/EUCAST breakpoints have been defined yet) in-vitro resistance to rifampicin and azithromycin was observed. WGS failed to determine classical AMR genes, and no difference in the distribution of virulence-associated genes in all isolates was found. Isolates of human and non-human origins were still susceptible to the majority of antibiotics used for treatment in humans. The absence of classical AMR genes in genomes of "resistant" Brucella strains may reflect a lack of information in databases, or resistance might not be encoded by single resistance genes. The One Health approach is necessary for tackling brucellosis. Continuous susceptibility testing, updating of breakpoints, assessing mutations that lead to resistance are needed.

Short- and long-term follow-up outcomes of patients with Brucella endocarditis: a systematic review of 207 Brucella endocarditis Cases

Brucella endocarditis is a fatal complication and the most frequent cause of death for human brucellosis. This study aimed to systematically review the literature on the follow-up outcomes of Brucella endocarditis and analyze the determinants affecting the follow-up outcomes. The databases PubMed, Web of Science, Embase, and Cochrane were searched using keywords and suitable combinations. All studies reporting the follow-up outcomes of Brucella endocarditis were included. Finally, a total of 76 studies (207 patients), including cases or case series, were included. The event rate for patients who underwent short- and long-term follow-up was 12.0% (2 relapsed and 1 died) and 8.1% (6 relapsed and 8 died), respectively. The differences in outcomes between different age groups (18–39, 40–59, and ≥60) were significant (P < 0.05, P = 0.035). The outcomes of the 18–39 age group were worse than those of the 40–59 age group (OR, 0.277; 95% CI, 0.103–0.748; P = 0.011). Accordingly, follow-up (both short- and long-term follow-up) is essential for Brucella endocarditis patients, especially for younger patients (18–39 years) in the first 6 months after treatment. The burden of Brucella endocarditis related complications were immense. Further studies are needed to explore age-based epidemiology of Brucella endocarditis and the exact influencing factors of the follow-up outcomes.

Epidemiology, Clinical and Laboratory Manifestations, and Outcomes of Brucellosis Among 104 Patients in Referral Hospitals of Tehran, Iran

Background: Brucellosis is the most common zoonotic disease in Iran, imposing a significant financial burden on the healthcare system. The diversity of non-specific clinical manifestations of this disease can lead to misdiagnosis or delayed diagnosis. Therefore, it is important to pay attention to other aspects of this disease. Objectives: This study aimed to determine the epidemiology, clinical and laboratory manifestations, and outcomes of brucellosis. Methods: In this cross-sectional study, brucellosis patients, admitted to three hospitals, affiliated to Shahid Beheshti University of Medical Sciences (Tehran, Iran) from April 2015 to September 2020, were examined. The patients' medical records were reviewed for epidemiological, clinical, and laboratory findings. The outcomes of the disease were evaluated by phone calls. Results: Of the 104 patients included in this study, 53.8% were male, and 46.2% were female. The mean age of the patients was 43.07 ± 18.521 years. Unpasteurized dairy consumption and contact with livestock were reported in 60.6 and 27.9% of the patients, respectively. Also, 23.1% of the patients had high-risk occupations. The most common symptoms included fever (80.8%), chills (58.7%), backache (55.8%), and sweating (51%). The most common complication was osteoarticular involvement (21.2%), followed by neurobrucellosis (6.7%). Elevated alkaline phosphatase (89.7%), anemia (67.3%), increased C-reactive protein (57.7%), and increased erythrocyte sedimentation rate (48.1%) were common laboratory findings. The rates of improvement, treatment failure, and relapse were 86.9, 9.1, and 4%, respectively. There was no significant relationship between the rate of improvement and the antibiotic regimen. However, the most common cause of treatment failure was the patient’s poor compliance with treatment. Conclusions: The diversity of non-specific clinical manifestations of brucellosis is a diagnostic challenge. Therefore, physicians must request laboratory tests to evaluate brucellosis after taking a precise epidemiological and clinical history of suspected cases.

Brucellosis in Saudi Children: Presentation, Complications, and Treatment Outcome

Background

Brucellosis, an endemic disease in Saudi Arabia, has an infection rate of 70 per 100,000 people, with a varying morbidity rate in different parts of the country. The aim of this study was to assess the epidemiological and clinical features, laboratory findings, treatment modalities, complications, and outcomes in children with brucellosis.

Materials and methods

The medical records of 153 patients attending King Abdullah Specialist Children’s Hospital in Riyadh, Saudi Arabia, from January 2015 to January 2019 were reviewed retrospectively. Demographic data, laboratory test results, serum agglutination test titer, and the results of the blood cultures were obtained. The diagnosis of brucellosis was based on compatible signs and symptoms with a positive serology titer of ≥1:160 or a blood culture positive for Brucella species.

Results

The majority of the sample (69.6%, n=107) were males, with a mean age of 7.75 ± 3.28 years. Ingestion of unpasteurized camel dairy products was the most frequent transmission risk factor. The most prevalent presenting symptoms were constitutional and musculoskeletal symptoms. Six patients (3.9%) had complicated brucellosis, with neurobrucellosis diagnosed in three cases. Hospitalization for brucellosis was required in 15% of the patients. The majority (99.35%, n=152) of the patients had a serum agglutination test (SAT) titer of ≥1:160. A blood culture was positive in 52 (34%) of the 111 patients tested. The most frequently prescribed regimen was rifampicin + co-trimoxazole in 81 (52.9%) patients. Relapse occurred in a small proportion (4.6%, n=7), and the majority (95.4%, n=146) had a complete remission.

Conclusions

The main route of transmission was the ingestion of unpasteurized dairy products. Brucellosis had a wide range of clinical presentation, involving multiple organ systems. Neurobrucellosis was the most frequent complication. The SAT was the most useful and reliable test for the diagnosis of brucellosis. Most patients were successfully treated with rifampicin and co-trimoxazole for six weeks.

Doxycycline-encapsulated solid lipid nanoparticles for the enhanced antibacterial potential to treat the chronic brucellosis and preventing its relapse: in vivo study

Background

Brucellosis is one of the most important infection of diseases. Due to its large period of treatment and survival ability of bacteria inside the macrophages, relapse of this disease is the main challenge, especially, after the treatment.

Objective

The current study was carried out to evaluate the antibacterial effect of solid lipid nanoparticles loaded with doxycycline on the Brucella melitensis in in vivo conditions.

Methods

The double emulsion synthesized doxycycline-encapsulated solid lipid nanoparticles (DOX-SLN) was characterized using DLS and FE-SEM. The efficacy of the DOX-SLN on the acute and chronic Wistar rat infected brucellosis was investigated. The pathological assessments were made on the spleen and liver in the treated rates.

Results

The in vivo experimental results demonstrated that the treated rats with DOX-SLN had significantly decreased the B. melitensis CFUs in their spleen and liver compared to that of the treated rates with free doxycycline and untreated ones. The pathologic results indicate that the improvement trend of spleen and liver tissues in rats treated by DOX-SLN was satisfactory.

Conclusion

According to in vivo results, the DOX-SLN has better effects on the treatment of chronic brucellosis. Therefore, DOX-SLN is recommended to treat the brucellosis and avoid its relapse.

An Outbreak of Brucellosis: An Adult and Pediatric Case Series

Background

Brucellosis is recognized as a neglected zoonotic disease and a major public health threat. The purpose of this study was to characterize epidemiological risk factors and healthcare utilization and compare clinical aspects of disease among adult and pediatric cases in North Texas.

Methods

A retrospective chart review of electronic medical records was completed at 3 large tertiary centers—Parkland Health and Hospital System, Clements University Hospital, and Children’s Medical Center—between January 1, 2007 and June 1, 2017. Demographic, clinical, and laboratory variables were collected. Cases were defined as confirmed or probable.

Results

Twenty-eight cases of brucellosis were identified: 26 confirmed (9 children, 17 adults) and 2 probable cases (1 child, 1 adult). Half (n = 14) were diagnosed in 2016 during an outbreak in Dallas County. Risk factors associated with infection were consumption of unpasteurized cheese (71%), recent travel (54%), close contact to a confirmed human brucellosis case (36%), and exposure to animals (11%). Median days of symptoms was 10 and 16 for children and adults, respectively. The majority (79%) of patients visited the emergency department before diagnosis and 93% were hospitalized. Fever was the most common symptom in children (80%) and adults (100%). Hepatitis (75% of children) and anemia (82% of adults) were the most common laboratory abnormalities. The most common complication in children was splenic lesions (40%), and the most common complication in adults was hepato/splenomegaly (39%).

Conclusions

The diagnosis of Brucella infection requires a high index of suspicion and should be considered in patients presenting with a febrile illness and a compatible exposure history.

Improved antibacterial function of Rifampicin-loaded solid lipid nanoparticles on Brucella abortus

The objective of this study was to assess the antibacterial activity of Rifampicin-loaded solid lipid nanoparticles on Brucella abortus 544. Rifampicin-loaded solid lipid nanoparticles were prepared by a modified microemulsion/sonication method and characterized. The results showed the average size about 319.7 nm, PI about 0.20 and zeta potential about 18.4 mv, encapsulation efficacy and drug-loading were equal to 95.78 and 34.2%, respectively, with a spherical shape. Drug release lasted for 5 days. The antibacterial activity was statistically significant with p < .05 in bacterial and cell culture media compared to free Rifampicin. It can be concluded that solid lipid nanoparticles can be considered as a promising delivery system for improving the antibacterial activity of Rifampicin against Brucella abortus.

Doxycycline-encapsulated solid lipid nanoparticles as promising tool against Brucella melitensis enclosed in macrophage: a pharmacodynamics study on J774A.1 cell line

Background

Brucellosis is a zoonotic disease caused by Brucella species. It has been estimated that more than 500,000 new cases of Brucellosis occur annually all around the world. Relapse of the disease is one of the most important challenges. The most important reason for the relapse of brucellosis is the survival of the bacteria inside the macrophages, which makes them safe from the immune system and disrupts drug delivery mechanism.

Objectives

The present study was performed to assess the effects of Doxycycline-loaded Solid Lipid Nanoparticles (DOX-SLN) on the Brucella melitensis inside macrophages.

Methods

DOX-SLN was prepared using double emulsion method. The technological characterization of DOX-SLN, including particle size, zeta potential, polydispersity index (PDI), drug loading and encapsulation efficiency were used. Fourier-transform infrared spectroscopy (FTIR) and Differential scanning calorimetry (DSC) were used to assess the interactions between Nanoparticles (NPs) components and crystalline form of doxycycline. Moreover, the effect of DOX-SLN on the bacteria were compared with that of the doxycycline using various methods, including well diffusion, Minimum Inhibitory Concentration (MIC), and investigation of their effects on murine macrophage-like cells cell line J774A.1.

Results

The means of particle size, zeta potential, PDI, drug loading and encapsulation efficiency were 299 ± 34 nm, − 28.7 ± 3.2 mV, 0.29 ± 0.027, 11.2 ± 1.3%, and 94.9 ± 3.2%, respectively. The morphology of NPs were spherical with a smooth surface. No chemical reaction was occurred between the components. Doxycycline was located within NP matrix in its molecular form. The DOX-SLN significantly decreased the microbial loading within macrophages (3.5 Log) in comparison with the free doxycycline.

Conclusions

Since the DOX-SLN showed better effects on B. melitensis enclosed in macrophages than the free doxycycline, it is recommended to use it for treating brucellosis and preventing relapse.

Persistence of Brucella abortus in the Bone Marrow of Infected Mice

Brucellosis is a zoonotic bacterial infection that may persist for long periods causing relapses in antibiotic-treated patients. The ability of Brucella to develop chronic infections is linked to their capacity to invade and replicate within the mononuclear phagocyte system, including the bone marrow (BM). Persistence of Brucella in the BM has been associated with hematological complications such as neutropenia, thrombocytopenia, anemia, and pancytopenia in human patients. In the mouse model, we observed that the number of Brucella abortus in the BM remained constant for up to 168 days of postinfection. This persistence was associated with histopathological changes, accompanied by augmented numbers of BM myeloid GMP progenitors, PMNs, and CD4+ lymphocytes during the acute phase (eight days) of the infection in the BM. Monocytes, PMNs, and GMP cells were identified as the cells harboring Brucella in the BM. We propose that the BM is an essential niche for the bacterium to establish long-lasting infections and that infected PMNs may serve as vehicles for dispersion of Brucella organisms, following the Trojan horse hypothesis. Monocytes are solid candidates for Brucella reservoirs in the BM.

Evaluation of Different Primers for Detection of Brucella by Using PCR Method

INTRODUCTION

Brucellosis is a worldwide zoonosis and a significant cause of loss of health in humans and animals. Traditionally, classic diagnosis is carried out by isolation of Brucella, which is time-consuming, technically challenging and potentially dangerous. The aim of this study was to expand a molecular test that would be used for the develop detection of Brucella in a single reaction with high sensitivity and specificity, by targeting IS711element.

METHODS

This study was carried out from 2015 to 2016 at the Ayatolla Rohani hospital in Babol, Iran. The present study was designed to develop PCR assay, based on IS711 gene for rapid diagnosis of Brucella spp. and immediate detection of Brucella, with high sensitivity and specificity. Four pairs of oligo-nucleotide primers with sizes of 547, 403, 291 and 127bp respectively, were planned to exclusively amplify the targeted genes of Brucella species.

RESULTS

Our results show that, five PCR primers set up, would be helpful in amplifying the DNAs from the genus Brucella with high specificity and sensitivity so it can be 12 fg, for Brucella species to provide a valuable tool for diagnosis.

CONCLUSION

This method can be more useful than serological and biochemical tests and in addition, this reduces the number of required tests more rapidly and economically.