Bacteria Of Brucella Research Articles

Three-Dimensional Structure of Full-Length NtrX, an Unusual Member of the NtrC Family of Response Regulators

Bacteria sense and adapt to environmental changes using two-component systems. These signaling pathways are formed by a histidine kinase that phosphorylates a response regulator (RR), which finally modulates the transcription of target genes.The bacterium Brucella abortus codes for a two-component system formed by the histidine kinase NtrY and the RR NtrX that participates in sensing low oxygen tension and generating an adaptive response. NtrX is a modular protein with REC, AAA+, and DNA-binding domains, an architecture that classifies it among the NtrC subfamily of RRs. However, it lacks the signature GAFTGA motif that is essential for activating transcription by the mechanism proposed for canonical members of this subfamily. In this article, we present the first crystal structure of full-length NtrX, which is also the first structure of a full-length NtrC-like RR with all the domains solved, showing that the protein is structurally similar to other members of the subfamily.We also report that NtrX binds nucleotides and the structures of the protein bound to ATP and ADP. Despite binding ATP, NtrX does not have ATPase activity and does not form oligomers in response to phosphorylation or nucleotide binding. We also identify a nucleotide sequence recognized by NtrX that allows it to bind to a promoter region that regulates its own transcription and to establish a negative feedback mechanism to modulate its expression. Overall, this article provides a detailed description of the NtrX RR and supports that it functions by a mechanism different to classical NtrC-like RRs.

Brucellosis: A Current Review Update on Zoonosis

Brucellosis is an infectious, contagious zoonotic disease which is spread worldwide, caused by bacteria of the genus Brucella. Brucellae are facultative intracellular parasites of the reticuloendothelial system and is characterised by wave-like variations in the body temperature of afflicted victims. It was formerly known as Mediterranean fever, Malta fever or undulant fever. Its modern name bears tribute to Sir David Bruce, the military physician who discovered the aetiologic agent, Brucella melitensis. The disease primarily affects cattle, sheep, goats, swine and dogs. The different Brucella spp. includes B. melitensis, Brucella abortus, Brucella canis and Brucella suis, and their preferential hosts are sheep/goats, cattle/bison, dogs and pigs, respectively. However, cross-species infections can occur; for example cattle can be affected by both B. abortus and B. melitensis at the same time [Abdussalam and Fein (1976). Developments in Biological Standardization, 31:23]. Hence, from epidemiological evidence, the three species (B. abortus, B. melitensis and B. suis) have distinct host preferences, and the organisms are capable to cause an infection in a wide range of host species, including humans. Cross transmission of brucellosis can occur between cattle, swine, sheep and goats and other species including dogs, horses, feral swine, bison, rein deer and camels [Than (2007). Prevalence survey of bovine brucellosis (Brucella abortus) in dairy cattle in Yangon, Myanmar. A Thesis Submitted to Chiang Mai University and Freie University at Berlin in a Partial Fulfilment of the Requirements for the Degree of Master of Veterinary Public Health].

Profile of knowledge producers on brucellosis in public health in Redenção Gurgueia - Piauí

Brucellosis is a zoonotic disease that causes major risks to public health and also great economic losses in livestock. It is an infectious disease caused by bacteria of the genus Brucella. Brucellosis in cattle received greater attention by the public bodies in recent years, culminating in the creation of PNCEBT with compulsory vaccination campaigns for female animals from 3 to 8 months old. The objective of this research, verify the knowledge of farmers about the importance of brucellosis to public health in the municipality of Gurgueia-PI of the Redenção. The research was conducted in the town of Redenção of Gurgueia-PI, located in the southern state of Piaui. According to the data collected from the small farmers it was observed that 45.5% of respondents producers know how to identify the signs of Brucellosis, but 54.5% are unaware of the clinicalsigns of the disease. The results in the survey revealed that farmers in the municipality of Redenção of Gurguéia-PI, is aware of the damage that Brucellosis can cause both the Animal Health as to public health. In addition, it was possible to see that most of the producers concerned and has also basic knowledge of the damage that may have, if there is the introduction and spread of the disease in their herds.

0099 In silico identification of natural product inhibitors of Brucella abortus threonyl-tRNA synthetase

Bovine brucellosis is mainly caused by the bacterium Brucella abortus, and represents a major problem to livestock industry development worldwide and is also a threat to human health in many developing and underdeveloped countries. Aminoacyl-tRNA synthetases (aaRSs), the central enzymes in protein translation, catalyze the covalent attachment of correct amino acids to their cognate tRNAs, yielding the aminoacyl tRNAs (aa-tRNA or charged tRNA) used for protein synthesis. Due to the pivotal role in protein synthesis, aaRSs have been considered as some of the most promising targets for antibiotics development in pathogenic species. In this study, a three-dimensional structural model of Brucella abortus threonyl-tRNA synthetase (BaThrRS) was constructed using computer-aided molecular modeling technique taking Escherichia coli threonyl-tRNA synthetase (EThrRS, PDB ID: 1QF6) as template. The ZINC natural product database including 11247 compounds was subjected for virtual screening based on molecular docking against the ATP binding site of the target using Autodock Vina program. Considering the mode of binding and affinities, seven leads, ZINC67910544 (–12.4 kcal/mol), ZINC72320615 (–12.3 kcal/mol), ZINC72320626 (–12.2 kcal/mol), ZINC27215482 (–12.6 kcal/mol), ZINC35270978 (–12.1 kcal/mol), ZINC35458951 (–12.1 kcal/mol), and ZINC42805205 (–12.4 kcal/mol) were selected on basis of binding energies in comparison to the selective inhibitor borrelidin (free energy of binding: –9.3 kcal/mol). Among them, ZINC27215482 (–12.6 kcal/mol) was best lead because of its highest inhibitory activity. The binding site of ZINC27215482 on BaThrRS was a pocket consisting of 22 residues: TYR316, ASN319, MET341, ASN342, CYS343, GLN374, MET383, ARG384, VAL385, PHE388, GLN390, ASP392, HIS394, TYR476, LYS479, GLN493, GLN498, THR496, GLN498, HIS525, SER531, and ARG534. Therefore, through a high throughput virtual screen we identified seven novel BaThrRS inhibitors that are used against bovine brucellosis with great potential for further development.

Comparative genomic analysis between newly sequenced Brucella suis Vaccine Strain S2 and the Virulent Brucella suis Strain 1330.

BackgroundBrucellosis is a bacterial disease caused by Brucella infection. In the late fifties, Brucella suis vaccine strain S2 with reduced virulence was obtained by serial transfer of a virulent B. suis biovar 1 strain in China. It has been widely used for vaccination in China since 1971. Until now, the mechanisms underlie virulence attenuation of S2 are still unknown.ResultsIn this paper, the whole genome sequencing of S2 was carried out by Illumina Hiseq2000 sequencing method. We further performed the comparative genomic analysis to find out the differences between S2 and the virulent Brucella suis strain 1330. We found premature stops in outer membrane autotransporter omaA and eryD genes. Single mutations were found in phosphatidylcholine synthase, phosphorglucosamine mutase, pyruvate kinase and FliF, which have been reported to be related to the virulence of Brucella or other bacteria. Of the other different proteins between S2 and 1330, such as Omp2b, periplasmic sugar-binding protein, and oligopeptide ABC transporter, no definitive implications related to bacterial virulence were found, which await further investigation.ConclusionsThe data presented here provided the rational basis for designing Brucella vaccines that could be used in other strains.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3076-5) contains supplementary material, which is available to authorized users.

The role of NLRP3 and AIM2 in inflammasome activation during Brucella abortus infection.

The innate immune system is essential for the detection and elimination of bacterial pathogens. Upon inflammasome activation, caspase-1 cleaves pro-IL-1β and pro-IL-18 to their mature forms IL-1β and IL-18, respectively, and the cell undergoes inflammatory death termed pyroptosis. Here, we reviewed recent findings demonstrating that Brucella abortus ligands activate NLRP3 and AIM2 inflammasomes which lead to control of infection. This protective effect is due to the inflammatory response caused by IL-1β and IL-18 rather than cell death. Brucella DNA is sensed by AIM2 and bacteria-induced mitochondrial reactive oxygen species is detected by NLRP3. However, deregulation of pro-inflammatory cytokine production can lead to immunopathology. Nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder termed neurobrucellosis. Herein, we discuss the mechanism of caspase-1 activation and IL-1β secretion in glial cells infected with B. abortus. Our results demonstrate that the ASC inflammasome is indispensable for inducing the activation of caspase-1 and secretion of IL-1β upon infection of astrocytes and microglia with Brucella. Moreover, our results demonstrate that secretion of IL-1β by Brucella-infected glial cells depends on NLRP3 and AIM2 and leads to neurobrucellosis. Further, the inhibition of the host cell inflammasome as an immune evasion strategy has been described for bacterial pathogens. We discuss here that the bacterial type IV secretion system VirB is required for inflammasome activation in host cells during infection. Taken together, our results indicate that Brucella is sensed by ASC inflammasomes mainly NLRP3 and AIM2 that collectively orchestrate a robust caspase-1 activation and pro-inflammatory response.

Cloning and molecular characterization of Omp31 gene from Brucella melitensis Rev 1 strain

Brucellosis, caused by the genus Brucella bacterium, is a well-known infection among domestic animals. Considering the serious economic and medical consequences of this infection, various preventive efforts have been made through using recombinant vaccines, based on outer membrane protein (OMP) antigens of Brucella species. The objective of the present study was to clone, analyze the sequence, and predict the epitopes of Omp31 gene as a major B. melitensis antigen. The full-length open reading frame (ORF) for this gene was amplified by specific primers and cloned into the pTZ57R/T vector. The gene sequence of B. melitensis Rev 1 strain was submitted to NCBI database. The results of phylogenetic analysis showed that Omp31 is almost similar in different Brucella species. Online prediction software programs were also used to predict B- and T-cell epitopes, secondary and tertiary structures, antigenicity, and enzymatic degradation sites. The bioinformatic tools in the current study were confirmed by the results of three different experimental epitope prediction studies. Bioinformatic analysis identified one T-cell and three B-cell epitopes for Omp31 antigen. Finally, based on the antigenicity and proteosome recognition sites, common B- and T-cell epitopes were predicted for Omp31 (amino acids 191-204). Bioinformatic analysis showed that these regions had proper epitope characterization and could be useful for recombinant vaccine development.

Activation of bovine neutrophils by Brucella spp

Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils.

The Detection of Brucella Bacteria with PCR and Bacteriological Method in Raw Milk and Some of the Dairy Products Which Are Consumed in Kars

Because of the abortus by the contamination to the humans via direct contact with infected animals or the consumption of contaminated raw milk and dairy products, brucellosis greatly causes to economic loss. For this reason, the annihilating of the effect of this disease is considerably important. Here, we aimed to detect the existence of Brucella bacteria in raw milk, cheese which is produced from raw milk and butter samples by using isolation, identification and PCR molecular techniques. Brucella type agents were detected in within a year by using 315 samples; 215 raw milk, 50 cheeses, 50 butter. Cheese and butter samples were obtained from raw milk. The grams coloring, oxidase, catalase, urease and H 2 S analysis of 215 raw milk samples showed that only 4 (%1.86) samples was Brucella positive. As a result, we have determined that there are several types of Brucellosis bacteria in milk, cheese and butter samples. Milk and dairy products can create a risk in Kars because of brucellosis.

Gene expression profiles predict treatment outcomes in Brucellosis

Abstract Brucellosis is a zoonotic disease caused by Brucella bacteria, acquired by humans through contact with or consumption of products from infected animals. Treatment outcomes vary widely; some patients recover, others relapse, and others develop chronic symptoms despite therapy. We employed expression profiling using RNA sequencing (RNAseq) to better understand variation in outcomes and investigate disease mechanisms. We performed RNAseq analysis of whole blood samples from 125 Brucellosis patients and 51 healthy controls from Macedonia. Patients were subdivided based on disease history into primary, secondary, and chronic infection. Secondary and chronic cases did not show differences in gene expression from healthy controls or from each other. Primary cases displayed numerous transcriptional changes relative to healthy controls. Up-regulated genes were enriched for response to interferon-gamma, cytolysis, T cell proliferation, and cell cycle; down-regulated genes, for B cell proliferation. Primary cases were further subdivided based on outcome into those who resolved with treatment and those who developed disease relapse during treatment. In comparison to healthy controls, relapse cases showed larger magnitude differences in expression at diagnosis than resolution cases; this suggests that relapse could potentially be predicted based on transcription levels at time of diagnosis. Differences in gene expression observed at diagnosis were no longer present 6–9 months after diagnosis. Our results indicate opportunities to prognostically identify patients that may require more intensive treatment and monitoring, and to better understand the symptomology of and immune response to Brucella infection.

In silico analysis of Omp25 and BLS Brucella melitensis antigens for designing subunit vaccine

Brucellosis is a well-known infection in domestic animals which caused by Brucella bacterium. Due to serious economic and medical consequences of this disease, various efforts have been made to prevent the infection through the use of recombinant vaccines based on Brucella outer membrane protein (OMP) antigens. The objectives of the present study were cloning, sequencing and epitope prediction of Omp25 and BLS genes as two major Brucella melitensis antigens. The full-length open reading frame (ORF) of Omp25 and BLS genes were amplified and cloned into pTZ57R/T vector. Phylogenetic analysis of sequenced genes showed that both genes were nearly similar in different Brucella species. Several online prediction softwares were used to predict B and T-cells epitopes, secondary and tertiary structures, antigenicity ability and enzymatic degradation sites. Bioinformatic tools used in the current study were confirmed by the results of three different experimental epitope predictions. Bioinformatic analysis identified five and two B-cell and two and one T-cell epitopes for Omp25 and BLS antigens, respectively. Finally, according to the antigenicity ability and proteosomal recognition site common B and T-cell epitope was predicted for Omp25 (154-162 amino acids) and BLS (37-48 and 119-139 amino acids). Results of this study might be useful for recombinant vaccine development.

Cloning, expression and molecular analysis of Iranian Brucella melitensis Omp25 gene for designing a subunit vaccine.

Brucellosis is a well-known domestic animal infectious disease, which is caused by Brucella bacterium. The outer membrane protein 25 kDa (Omp25) gene plays an important role in simulating of TNF-α, IFN-α, macrophage, and cytokines cells. In the current study molecular cloning and expression analysis of Omp25 gene for designing a subunit vaccine against Brucella was investigated. Amplifying the full length of candidate gene was performed using specific primers. Sub-cloning of this gene conducted using pTZ57R/T vector in TOP10F strain of Escherichia coli(E.coli) as the host. Also, pET32(a)+ vector used for expression in BL21 (DE3) strain of E.coli. Omp25 gene with 642 bp size was amplified and cloned successfully. The expression results were confirmed by sequencing and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analyses which showed 42 kDa protein band correctly. Also, phylogenic analysis showed this gene has a near genetic relation with other Brucella strains. According to our results we can propose this gene as a candidate useful for stimulation of cell-mediated and humoral immunity system in future study.

Infectious sacroiliitis in tunisian centre: retrospective study of 25 cases

Les sacroiliites infectieuses sont rares mais peuvent se compliquer de séquelles fonctionnelles invalidantes. Décrire les caractéristiques cliniques et bactériologiques des sacroiliites infectieuses chez les patients suivis à Sousse, Centre Tunisien. Etude rétrospective, descriptive, des cas de sacroiliites infectieuses chez les patients hospitalisés à Sousse entre 2000 et 2015. Le diagnostic a été retenu devant des signes cliniques, d'imagerie, et microbiologiques évocateurs. Vingt-cinq patients, 10 hommes et 15 femmes, d’âge moyen 41 ans (19-78) ont été inclus. Les sacroiliites étaient dues à des bactéries pyogènes dans 14 cas (56%), brucelliennes dans 6 cas (24%), et tuberculeuses dans 5 cas (20%). La durée moyenne d’évolution était de 61, 45 et 402 jours respectivement. Les signes cliniques les plus fréquents étaient les douleurs fessières (92%) et la fièvre (88%). La radiographie standard était anormale dans 75% des cas. La TDM et l'IRM sacro-iliaques dans tous les cas. Le diagnostic a été confirmé bactériologiquement dans 24 cas (96%). La durée moyenne d'antibiothérapie était de 83 jours dans les sacroiliites à pyogènes, et de 102 jours dans les SI brucelliennes. L’évolution était favorable chez 12 patients (48%), 9 patients (36%) ont gardé une douleur sacro-iliaque séquellaire, et 4 patients (16%) sont décédés. Dans notre étude, la durée d’évolution de la sacroiliite infectieuse ne permettait pas de prédire la bactérie responsable, d'où la nécessité d'obtenir une documentation bactériologique afin de prescrire une antibiothérapie appropriée.

Molecular aspects of Brucella persistence

Brucellosis is a dangerous zoonotic disease of animals and humans caused by bacteria of the genus Brucella, which are able to survive, multiply, and persist in host cells. The review is devoted to the Brucella species persistence connected to the molecular mechanisms of escape from innate and adaptive immunity of the host and active interaction of effector proteins of the type IV secretion system with the host's signaling pathways. Understanding of the molecular mechanisms used by Brucella for the intracellular persistence in the host organism can allow us to develop new and effective means for the prevention and treatment of chronic brucellosis infection.

Molecular aspects of Brucella persistence

Brucellosis is a dangerous zoonotic disease of animals and humans caused by bacteria of the genus Brucella, which are able to survive, multiply, and persist in host cells. The review is devoted to the Brucella species persistence connected to the molecular mechanisms of escape from innate and adaptive immunity of the host and active interaction of effector proteins of the type IV secretion system with the host's signaling pathways. Understanding of the molecular mechanisms used by Brucella for the intracellular persistence in the host organism can allow us to develop new and effective means for the prevention and treatment of chronic brucellosis infection.

Brucella spp. Virulence Factors and Immunity.

Brucellosis, caused by bacteria of the genus Brucella, is an important zoonotic infection that causes reproductive disease in domestic animals and chronic debilitating disease in humans. An intriguing aspect of Brucella infection is the ability of these bacteria to evade the host immune response, leading to pathogen persistence. Conversely, in the reproductive tract of infected animals, this stealthy pathogen is able to cause an acute severe inflammatory response. In this review, we discuss the different mechanisms used by Brucella to cause disease, with emphasis on its virulence factors and the dichotomy between chronic persistence and reproductive disease.

Comparative transcriptome analysis of Brucella melitensis in an acidic environment: Identification of the two-component response regulator involved in the acid resistance and virulence of Brucella

Brucella melitensis, encounters a very stressful environment in phagosomes, especially low pH levels. So identifying the genes that contribute to the replication and survival within an acidic environment is critical in understanding the pathogenesis of the Brucella bacteria. In our research, comparative transcriptome with RNA-seq were used to analyze the changes of genes in normal-medium culture and in pH4.4-medium culture. The results reveal that 113 genes expressed with significant differences (|log2Ratio| ≥ 3); about 44% genes expressed as up-regulated. With GO term analysis, structural constituent of the ribosome, rRNA binding, structural molecule activity, and cation-transporting ATPase activity were significantly enriched (p-value ≤ 0.05). These genes distributed in 51 pathways, in which ribosome and photosynthesis pathways were significantly enriched. Six pathways (oxidative phosphorylation, iron-transporting, bacterial secretion system, transcriptional regulation, two-component system, and ABC transporters pathways) tightly related to the intracellular survival and virulence of Brucella were analyzed. A two-component response regulator gene in the transcriptional regulation pathway, identified through gene deletion and complementary technologies, played an important role in the resistance to the acid-resistance and virulence of Brucella.

English

Brucellosis is a cosmopolitan zoonotic disease that affects man, domestic animals and wildlife. The bacteria Brucella abortus is the principle cause of brucellosis in cattle. The incidence of the disease in humans, and which directly relates to that in other animals, is highly dependent on animal husbandry practices, the interaction between humans and animals, living standards, hygiene, food customs, and animal and human population density. Makuyu Division where the study was undertaken experiences hot and dry climate, the area has no permanent rivers and domestic water is obtained from boreholes. Most families live in congested homes and are provided with relieve food by the Government. The standard of hygiene is very low and most of the people are poor. In August 2009 six cases of retained placenta disease were reported to Makuyu veterinary Department among other diseases. Most people are readily exposed to infected animals or indirectly to milk, water and environment contaminated by brucellosis. It is for these reasons that the study was undertaken with the aim to determine prevalence of Brucella abortus in dairy cattle and assess knowledge of the disease among the dairy farmers. The study involved random sampling of dairy cattle in the division and a representative sample of two hundred and eight milk and blood samples were collected. The samples were screened at the Central Veterinary Laboratories, Kabete. Immunological tests were used to test presence of Brucella abortus antibodies. A questionnaire was used to assess knowledge of brucellosis among the dairy farmers and determine utilization and accessibility to veterinary services. Data analysis involved descriptive statistics to obtain prevalence rate. The percentage prevalence of brucellosis in dairy cattle as determined by both MRT and RBPT were 7.7% and 1.9% respectively. Knowledge of brucellosis was significantly related to the age and level of education of the farmers. The young and educated farmers were more knowledgeable on brucellosis than those who were old and not educated. The old and not educated were the majority and they had no idea on what causes brucellosis in cattle. The Ministries of Health and Agriculture, Livestock and Fisheries will use the results in targeting education and prevention programs to address the disease. Farmers will be educated on methods of controlling brucellosis to reduce prevalence, use of artificial insemination to reduce venereal transmission of brucellosis during mating, herd health campaign with frequent screening for brucellosis to identify infected animals so that they can be slaughtered to eradicate the disease and food and occupational hygiene to prevent transmission of brucellosis to human beings.

Brucellosis in Sub-Saharan Africa: Current challenges for management, diagnosis and control

Brucellosis is a highly contagious zoonosis caused by bacteria of the genus Brucella and affecting domestic and wild mammals. In this paper, the bacteriological and serological evidence of brucellosis in Sub-Saharan Africa (SSA) and its epidemiological characteristics are discussed. The tools available for the diagnosis and treatment of human brucellosis and for the diagnosis and control of animal brucellosis and their applicability in the context of SSA are presented and gaps identified. These gaps concern mostly the need for simpler and more affordable antimicrobial treatments against human brucellosis, the development of a B. melitensis vaccine that could circumvent the drawbacks of the currently available Rev 1 vaccine, and the investigation of serological diagnostic tests for camel brucellosis and wildlife. Strategies for the implementation of animal vaccination are also discussed.

Aspectos da brucelose na saúde pública veterinária

The brucellosis is an infectious disease of chronic evolution and character typical granulomatous disease mainly affecting the reproductive system and the musculoskeletal domestic animals, wildlife and humans. It's a anthropozoonosis characterized by infection of the cells of the mononuclear phagocyte system, caused by bacteria of the genus Brucella. With worldwide distribution, in our country has a high incidence and prevalence in cattle, serving as the main source of infection for humans. Although a character occupational illness affecting workers who are in direct contact with sick animals, also features character population, because the intake of animal products contanimados become important means of transmission of this bacterium. Although it is characterized by a serious zoonotic disease, this disease is still poorly understood by many people because of the many understatements.