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comparative proteomics analyses reveal the virb of b. melitensis affects expression of intracellular survival related proteins.brucella melitensis is a facultative, intracellular, pathogenic bacterium that replicates within macrophages. the type iv secretion system encoded by the virb operon (virb) is involved in brucella intracellular survival. however, the underlying molecular mechanisms, especially the target proteins affected by the virb, remain largely unclear.200919401764
pathogenicity of different strains of histophilus somni in the experimental induction of ovine epididymitis.the purpose of this study was to determine any differences in pathogenicity when sheep are experimentally infected with different histophilus somni isolates: a) 2336 bovine origin strain; b) an isolate from ram orchitis and epididymitis; c) an isolate from the brain of a sheep with neurological signs; d) an isolate from the vagina of a clinically healthy ewe. a total of 20 rams divided in groups of 5 animals each were inoculated in the epididymis with 1 x 10(7) cfu/ml of h. somni; a negative con ...200919436586
genome degradation in brucella ovis corresponds with narrowing of its host range and tissue tropism.brucella ovis is a veterinary pathogen associated with epididymitis in sheep. despite its genetic similarity to the zoonotic pathogens b. abortus, b. melitensis and b. suis, b. ovis does not cause zoonotic disease. genomic analysis of the type strain atcc25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of b. ovis. th ...200919436743
design and influence of gamma-irradiation on the biopharmaceutical properties of nanoparticles containing an antigenic complex from brucella ovis.despite vaccination campaigns, brucellosis is still one of the most common bacterial zoonosis in the world. this work describes the development of a novel formulation strategy to the delivery of the brucella ovis antigenic extract (hs) into ovine mucosal surfaces. thus, hs was entrapped in conventional and mannosylated poly(anhydride) nanoparticles by the solvent displacement method, and the resulting nanosystems were gamma-irradiated to accomplish the sterilization required for the ophthalmic a ...200919442721
first evidence of brucella ovis infection in republic of croatia.we researched the spread of brucella ovis (b. ovis) infection in sheep during 2002 and 2003 in croatia. a total of 30,635 sheep blood samples were examined using the enzyme-linked immunosorbent assay (elisa). in 2002, 1014 out of 14,404 examined sheep blood samples (7%) from six counties gave positive reactions while 2060 (14.3%) were found suspicious. in 2003, 638 out of 16,221 examined sheep blood samples in nine counties (3.9%) tested positive while 1083 (6.7%) were suspicious. in rams and sh ...200919537042
a novel nanoparticulate adjuvant for immunotherapy with lolium perenne.specific immunotherapy implies certain drawbacks which could be minimized by the use of appropriate adjuvants, capable of amplifying the right immune response with minimal side effects. in this context, previous studies of our group have demonstrated the adjuvant capacity of gantrez an nanoparticles, which can effectively enhance the immune response. in this work, two types of nanoparticles (with and without lps of brucella ovis as immunomodulator) with encapsulated lolium perenne extract are te ...200919545572
rapid real-time pcr assays for detection of klebsiella pneumoniae with the rmpa or maga genes associated with the hypermucoviscosity phenotype: screening of nonhuman primates.the relationship of mucoviscosity-associated (maga) and/or regulator of mucoid phenotype (rmpa) genes to the klebsiella pneumoniae hypermucoviscosity (hmv) phenotype has been reported. we previously demonstrated that rmpa+ k. pneumoniae can cause serious disease in african green monkeys and isolated rmpa+ and maga+ hmv k. pneumoniae from other species of non-human primates. to rapidly screen african green monkeys/non-human primates for these infections, we developed three real-time pcr assays. t ...200919644019
mutation of his465 alters the ph-dependent spectroscopic properties of escherichia coli glutamate decarboxylase and broadens the range of its activity toward more alkaline ph.glutamate decarboxylase (gadb) from escherichia coli is a hexameric, pyridoxal 5'-phosphate-dependent enzyme catalyzing co(2) release from the alpha-carboxyl group of l-glutamate to yield gamma-aminobutyrate. gadb exhibits an acidic ph optimum and undergoes a spectroscopically detectable and strongly cooperative ph-dependent conformational change involving at least six protons. crystallographic studies showed that at mildly alkaline ph gadb is inactive because all active sites are locked by the ...200919797049
survival of the fittest: how brucella strains adapt to their intracellular niche in the host.brucella strains produce abortion and infertility in their natural hosts and a zoonotic disease in humans known as undulant fever. these bacteria do not produce classical virulence factors, and their capacity to successfully survive and replicate within a variety of host cells underlies their pathogenicity. extensive replication of the brucellae in placental trophoblasts is associated with reproductive tract pathology in natural hosts, and prolonged persistence in macrophages leads to the chroni ...200919830453
evaluation of particulate acellular vaccines against brucella ovis infection in rams.the attenuated brucella melitensis rev 1 vaccine, used against brucellosis infection, interferes with serological diagnosis tests, may induce abortions in pregnant animals, and may infect humans. in order to overcome these drawbacks, we developed acellular vaccines based on a brucella ovis antigenic complex (hs) containing outer membrane proteins and r-lps entrapped in poly(anhydride) conventional and mannosylated nanoparticles (np-hs and man-np-hs) or in poly(epsilon-caprolactone) microparticle ...201019887131
brucella melitensis, b. neotomae and b. ovis elicit common and distinctive macrophage defense transcriptional responses.brucella spp. establish an intracellular replicative niche in macrophages, while macrophages attempt to eliminate the bacteria by innate defense mechanisms. brucella spp. possess similar genomes yet exhibit different macrophage infections. few b. melitensis and b. neotomae enter macrophages with intracellular adaptation occurring over 4-8 hr. conversely, b. ovis are readily ingested by macrophages and exhibit a persistent plateau of infection. evaluating early macrophage interaction with brucell ...200919934366
cholesterol, ganglioside gm1 and class a scavenger receptor contribute to infection by brucella ovis and brucella canis in murine macrophages.the establishment of infection by brucella ovis and brucella canis in j774.a1 macrophages was found to be dependent upon cholesterol and ganglioside gm(1), two components of lipid rafts. this process also required a class a scavenger receptor of macrophages, and was not inhibited by smooth and rough lipopolysaccharides from brucella spp. in response to infection, both bacteria induced a weak degree of macrophage activation. these results demonstrate that b. ovis and b. canis use cell surface rec ...201020083220
atp-binding cassette systems of brucella.brucellosis is a prevalent zoonotic disease and is endemic in the middle east, south america, and other areas of the world. in this study, complete inventories of putative functional abc systems of five brucella species have been compiled and compared. abc systems of brucella melitensis 16m, brucella abortus 9-941, brucella canis rm6/66, brucella suis 1330, and brucella ovis 63/290 were identified and aligned. high numbers of abc systems, particularly nutrient importers, were found in all brucel ...201020169092
development and evaluation of a species-specific pcr assay for the detection of brucella ovis infection in rams.brucella ovis infection is a major cause of epididymitis and infertility in rams, resulting in reproductive failure and significant economic losses worldwide. the goal of this study was to develop a pcr test targeting specific b. ovis genomic sequences. specific primer pairs were designed targeting 12 of those orfs. samples of blood, serum, semen, urine, and preputial wash were collected from experimentally infected rams (n=9) every other week up to 180 days post infection (dpi), when tissue sam ...201020347534
pentaplexed quantitative real-time pcr assay for the simultaneous detection and quantification of botulinum neurotoxin-producing clostridia in food and clinical samples.botulinum neurotoxins are produced by the anaerobic bacterium clostridium botulinum and are divided into seven distinct serotypes (a to g) known to cause botulism in animals and humans. in this study, a multiplexed quantitative real-time pcr assay for the simultaneous detection of the human pathogenic c. botulinum serotypes a, b, e, and f was developed. based on the taqman chemistry, we used five individual primer-probe sets within one pcr, combining both minor groove binder- and locked nucleic ...201020435756
the feasibility of using antigens prepared with rough brucella strains for diagnosis of canine brucellosis.clinical diagnosis of canine brucellosis is not sensitive enough and a negative blood culture cannot rule out the disease. indirect methods of serological testing such as agar gel immunodiffusion (agid), rapid slide agglutination test (rsat) and indirect enzyme linked immunoassay (ielisa) are preferred for routine diagnosis. since brucella canis shares antigenic components with the brucella ovis and brucella abortus rb51 strain, it would seem that either strain could be used as antigen. we prese ...201020461292
proteomics-based confirmation of protein expression and correction of annotation errors in the brucella abortus genome.brucellosis is a major bacterial zoonosis affecting domestic livestock and wild mammals, as well as humans around the globe. while conducting proteomics studies to better understand brucella abortus virulence, we consolidated the proteomic data collected and compared it to publically available genomic data.201020462421
brucella taxonomy and evolution.taxonomy and nomenclature represent man-made systems designed to enhance understanding of the relationship between organisms by comparison of discrete sets of properties. initial efforts at bacterial taxonomy were flawed as a result of the previous use of nonsystematic approaches including common names resulting in confusing and inaccurate nomenclature. a decision was made to start afresh with bacterial nomenclature and to avoid the hazards experienced in the taxonomic classification of higher o ...201020521932
genomic comparisons of brucella spp. and closely related bacteria using base compositional and proteome based methods.classification of bacteria within the genus brucella has been difficult due in part to considerable genomic homogeneity between the different species and biovars, in spite of clear differences in phenotypes. therefore, many different methods have been used to assess brucella taxonomy. in the current work, we examine 32 sequenced genomes from genus brucella representing the six classical species, as well as more recently described species, using bioinformatical methods. comparisons were made at t ...201020707916
effect of extender supplementation with various antimicrobial agents on viability of brucella ovis and actinobacillus seminis in cryopreserved ovine semen.the objective was to determine the effectiveness of various antimicrobial agents added to semen extender for inactivation of b. ovis or a. seminis in ovine semen after cryopreservation. in experiment 1, 20 ejaculates from a crossbred ram infected with b. ovis were cryopreserved in tris-based extenders with various antimicrobial agents: (i) control without antibiotics, (ii) with penicillin and streptomycin (1000 iu/ml and 1 mg/ml, respectively), (iii) lincomycin (0.15 mg/ml), (iv) sulphadiazine ( ...201020708246
diagnosis of brucellosis in livestock and wildlife.to describe and discuss the merits of various direct and indirect methods applied in vitro (mainly on blood or milk) or in vivo (allergic test) for the diagnosis of brucellosis in animals.201020718082
obstacles of multiplex real-time pcr for bacterial 16s rdna: primer specifity and dna decontamination of taq polymerase.background: the detection of a broad range of bacteria by pcr is applied for the screening of blood and blood products with special attention to platelet concentrates. for practical use it is desirable that detection systems include gram-positive, gram-negative and non-gram-stainable bacteria. it is quite challenging to achieve high sensitivity along with a clear negative control with pcr reagents, because especially taq polymerase is contaminated with traces of bacterial dna. methods: bacterial ...201020737013
genomic island 2 is an unstable genetic element contributing to brucella lipopolysaccharide spontaneous smooth-to-rough dissociation.brucella is a gram-negative bacterium that causes a worldwide-distributed zoonosis. the genus includes smooth (s) and rough (r) species that differ in the presence or absence, respectively, of the o-polysaccharide of lipopolysaccharide. in s brucellae, the o-polysaccharide is a critical diagnostic antigen and a virulence determinant. however, s brucellae spontaneously dissociate into r forms, a problem in antigen and s vaccine production. spontaneous r mutants of brucella abortus, brucella melit ...201020952568
ribosomal rna sequence analysis of brucella infection misidentified as ochrobactrum anthropi infection.a brucella isolate was identified from purulent material collected during a hip surgery. two previous blood cultures from the same patient yielded ochrobactrum anthropi. after rrna sequencing, all the isolates were identified as brucella species and subsequently serotyped as brucella suis. misidentification of brucella species remains a problem with bacterial identification systems.201121209167
control of brucella ovis infection in sheep.approach to control of brucella ovis would vary in different countries and areas depending on farm and flock characteristics and economic factors. eradication by a test-and-slaughter approach is the most desirable option in areas where it is logistically and financially feasible. vaccination is used in areas with a high incidence of infection where eradication would be difficult. voluntary accreditation programs have been established in some countries and are of particular benefit to pedigree ra ...201121215890
development of a selective culture medium for primary isolation of the main brucella species.bacteriological diagnosis of brucellosis is performed by culturing animal samples directly on both farrell medium (fm) and modified thayer-martin medium (mtm). however, despite inhibiting most contaminating microorganisms, fm also inhibits the growth of brucella ovis and some b. melitensis and b. abortus strains. in contrast, mtm is adequate for growth of all brucella species but only partially inhibitory for contaminants. moreover, the performance of both culture media for isolating b. suis has ...201121270216
putative atp-binding cassette transporter is essential for brucella ovis pathogenesis in mice.brucella ovis is a major cause of reproductive failure in sheep, which is associated with epididymitis and infertility in rams. importantly, b. ovis is one of the few brucella species that is not zoonotic. due to the scarcity of studies on b. ovis infection, a murine model of infection was developed. the roles of b. ovis genes encoding a putative hemagglutinin and an abc transporter were investigated in the mouse model. the kinetics of b. ovis infection were similar in balb/c and c57bl/6 mice, a ...201121300772
laboratory animal models for brucellosis research.brucellosis is a chronic infectious disease caused by brucella spp., a gram-negative facultative intracellular pathogen that affects humans and animals, leading to significant impact on public health and animal industry. human brucellosis is considered the most prevalent bacterial zoonosis in the world and is characterized by fever, weight loss, depression, hepato/splenomegaly, osteoarticular, and genital infections. relevant aspects of brucella pathogenesis have been intensively investigated in ...201121403904
a species independent universal bio-detection microarray for pathogen forensics and phylogenetic classification of unknown microorganisms.the ability to differentiate a bioterrorist attack or an accidental release of a research pathogen from a naturally occurring pandemic or disease event is crucial to the safety and security of this nation by enabling an appropriate and rapid response. it is critical in samples from an infected patient, the environment, or a laboratory to quickly and accurately identify the precise pathogen including natural or engineered variants and to classify new pathogens in relation to those that are known. ...201121672191
protective live oral brucellosis vaccines stimulate th1 and th17 cell responses.zoonotic transmission of brucellosis often results from exposure to brucella-infected livestock, feral animals, or wildlife, or frequently via consumption of unpasteurized milk products or raw meat. since natural infection of humans often occurs by the oral route, mucosal vaccination may offer a means to confer protection for both mucosal and systemic tissues. significant efforts have focused on developing a live brucellosis vaccine, and deletion of znua gene involved in zinc transport has been ...201121768283
biological warfare agents.the recent bioterrorist attacks using anthrax spores have emphasized the need to detect and decontaminate critical facilities in the shortest possible time. there has been a remarkable progress in the detection, protection and decontamination of biological warfare agents as many instrumentation platforms and detection methodologies are developed and commissioned. even then the threat of biological warfare agents and their use in bioterrorist attacks still remain a leading cause of global concern ...201021829313
course of infection in immunocompromised mice with the emergent pathogen brucella microti.a new brucella species brucella microti has been isolated from wild rodents and found to be pathogenic in mice. the biological relevance of this new mouse pathogen is clear as it allows us to study brucella infection in a species-specific model. the course of infection in wild type (wt) and immunodeficient mice that lack b (jh), t and b (scid) or t, b and nk (scid.beige) cells was analysed during three weeks. wt mice completely cleared bacteria from liver and spleen after that time. however, sci ...201121825066
an improved immunoblotting technique for the serodiagnosis of brucella ovis infections. 199722133200
leptospirosis as the most frequent infectious disease impairing productivity in small ruminants in rio de janeiro, brazil.despite the importance of small ruminants breeding in developing countries, milk/meat productivity remains unsatisfactory. infectious diseases, such as leptospirosis, brucellosis, and small ruminant lentiviruses (srlvs), contribute to this scenario. the objective of the present study was to determine the role of each of these diseases in the productivity of small ruminants breeding in rio de janeiro, brazil. in goats, 343 samples were tested for leptospirosis, 560 for brucella abortus, and 506 f ...201121898182
brucellosis ontology (idobru) as an extension of the infectious disease ontology.abstract:201122041276
revised genome sequence of brucella suis 1330.brucella suis is a causative agent of porcine brucellosis. we report the resequencing of the original sample upon which the published sequence of brucella suis 1330 is based and describe the differences between the published assembly and our assembly at 12 loci.201122038969
The Brucella TIR-like protein TcpB interacts with the death domain of MyD88.The pathogen Brucella melitensis secretes a Toll/interleukin-1 receptor (TIR) domain containing protein that abrogates host innate immune responses. In this study, we have characterized the biochemical interactions of Brucella TIR-like protein TcpB with host innate immune adaptor proteins. Using protein-fragment complementation assays based on Gaussia luciferase and green fluorescent protein, we find that TcpB interacts directly with MyD88 and that this interaction is significantly stronger than ...201122155231
The Brucella TIR-like protein TcpB interacts with the death domain of MyD88.The pathogen Brucella melitensis secretes a Toll/interleukin-1 receptor (TIR) domain containing protein that abrogates host innate immune responses. In this study, we have characterized the biochemical interactions of Brucella TIR-like protein TcpB with host innate immune adaptor proteins. Using protein-fragment complementation assays based on Gaussia luciferase and green fluorescent protein, we find that TcpB interacts directly with MyD88 and that this interaction is significantly stronger than ...201122155231
PATRIC: the comprehensive bacterial bioinformatics resource with a focus on human pathogenic species.Funded by the National Institute of Allergy and Infectious Diseases, the Pathosystems Resource Integration Center (PATRIC) is a genomics-centric relational database and bioinformatics resource designed to assist scientists in infectious-disease research. Specifically, PATRIC provides scientists with (i) a comprehensive bacterial genomics database, (ii) a plethora of associated data relevant to genomic analysis, and (iii) an extensive suite of computational tools and platforms for bioinformatics ...201121896772
Reliable identification at the species level of Brucella isolates with MALDI-TOF-MS.ABSTRACT: BACKGROUND: The genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a rapid method for the analysis of biological samples. The advantages of this method, compared to co ...201122192890
Intra-species biodiversity of the genetically homologous species Brucella microti.Brucellosis is one of the major bacterial zoonoses worldwide. In the last decade, an increasing number of atypical Brucella strains and species have been described. Brucella microti in particular attracted attention because this species not only infects mammalian hosts but also persists in soil. An environmental reservoir may pose a new public health risk leading to the re-emergence of brucellosis. In a polyphasic approach, comprising conventional microbiological, extensive biochemical and molec ...201122210211
deep-sequencing analysis of the mouse transcriptome response to infection with brucella melitensis strains of differing virulence.brucella melitensis is an important zoonotic pathogen that causes brucellosis, a disease that affects sheep, cattle and occasionally humans. b. melitensis strain m5-90, a live attenuated vaccine cultured from b. melitensis strain m28, has been used as an effective tool in the control of brucellosis in goats and sheep in china. however, the molecular changes leading to attenuated virulence and pathogenicity in b. melitensis remain poorly understood. in this study we employed the illumina genome a ...201122216095
identification of the virb operon genes encoding the type iv secretion system, in colombian brucella canis isolates.canine brucellosis is a zoonotic disease caused by brucella canis. the establishment of intracellular replicative niches of b. canis is mediated by proteins secreted by the type iv secretion system, which is encoded by the virb operon. the characterization of such genes has been conducted in other species of the genus, but not in b. canis. we report the design of a multiplex pcr test for the detection of the virb operon genes of b. canis. primers for each of the 12 genes were designed and evalua ...201223290573
cell mediated immune response after challenge in omp25 liposome immunized mice contributes to protection against virulent brucella abortus 544.brucellosis is a disease affecting various domestic and wild life species, and is caused by a bacterium brucella. keeping in view the serious economic and medical consequences of brucellosis, efforts have been made to prevent the infection through the use of vaccines. cell-mediated immune responses [cmi] involving interferon gamma and cytotoxic cd4(+) and cd8(+) t cells are required for removal of intracellular brucella. omp25 has been reported to be involved in virulence of brucella melitensis, ...201223273966
annotation of protein domains reveals remarkable conservation in the functional make up of proteomes across superkingdoms.the functional repertoire of a cell is largely embodied in its proteome, the collection of proteins encoded in the genome of an organism. the molecular functions of proteins are the direct consequence of their structure and structure can be inferred from sequence using hidden markov models of structural recognition. here we analyze the functional annotation of protein domain structures in almost a thousand sequenced genomes, exploring the functional and structural diversity of proteomes. we find ...201124710297
assessment of real-time pcr assay for detection of rickettsia spp. and rickettsia rickettsii in banked clinical samples.two novel real-time pcr assays were developed for the detection of rickettsia spp. one assay detects all tested rickettsia spp.; the other is specific for rickettsia rickettsii. evaluation using dna from human blood and tissue samples showed both assays to be more sensitive than nested pcr assays currently in use at the cdc.201323135935
analyzing the molecular mechanism of lipoprotein localization in brucella.bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. as such many lipoproteins, originating from brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. these membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. although much research has focused on the identification and classificatio ...201526579096
challenges with using names to link digital biodiversity information. 201627346955
a flood of microbial genomes-do we need more? 200919513110
atp-binding cassette transporters are targets for the development of antibacterial vaccines and therapies. 200415557595
functional genes to assess nitrogen cycling and aromatic hydrocarbon degradation: primers and processing matter.targeting sequencing to genes involved in key environmental processes, i.e., ecofunctional genes, provides an opportunity to sample nature's gene guilds to greater depth and help link community structure to process-level outcomes. vastly different approaches have been implemented for sequence processing and, ultimately, for taxonomic placement of these gene reads. the overall quality of next generation sequence analysis of functional genes is dependent on multiple steps and assumptions of unknow ...201324062736
insertion sequences.insertion sequences (iss) constitute an important component of most bacterial genomes. over 500 individual iss have been described in the literature to date, and many more are being discovered in the ongoing prokaryotic and eukaryotic genome-sequencing projects. the last 10 years have also seen some striking advances in our understanding of the transposition process itself. not least of these has been the development of various in vitro transposition systems for both prokaryotic and eukaryotic e ...19989729608
tir domain-containing adaptor sarm is a late addition to the ongoing microbe-host dialog.toll/interleukin-1 receptor (tir) domain-containing proteins play important roles in defense against pathogens in both animals and plants, connecting the immunity signaling pathways via a chain of specific protein-protein interactions. among them is sarm, the only tir domain-containing adaptor that can negatively regulate tlr signaling. by extensive phylogenetic analysis, we show here that sarm is closely related to bacterial proteins with tir domains, suggesting that this family has a different ...201021110998
tir domain-containing adaptor sarm is a late addition to the ongoing microbe-host dialog.toll/interleukin-1 receptor (tir) domain-containing proteins play important roles in defense against pathogens in both animals and plants, connecting the immunity signaling pathways via a chain of specific protein-protein interactions. among them is sarm, the only tir domain-containing adaptor that can negatively regulate tlr signaling. by extensive phylogenetic analysis, we show here that sarm is closely related to bacterial proteins with tir domains, suggesting that this family has a different ...201021110998
development of a novel genus-specific real-time pcr assay for detection and differentiation of bartonella species and genotypes.the genus bartonella includes numerous species with varied host associations, including several that infect humans. development of a molecular diagnostic method capable of detecting the diverse repertoire of bartonella species while maintaining genus specificity has been a challenge. we developed a novel real-time pcr assay targeting a 301-bp region of the ssra gene of bartonella and demonstrated specific amplification in over 30 bartonella species, subspecies, and strains. subsequent analysis o ...201222378904
characterization of the vaginal microbiota of ewes and cows reveals a unique microbiota with low levels of lactobacilli and near-neutral ph.although a number of common reproductive disorders in livestock involve bacterial infection, very little is known about their normal vaginal microbiota. therefore, we sought to determine the species composition of sheep and cattle vaginal microbiota. twenty rambouillet ewes and twenty crossbred cows varying in age and reproductive status were sampled by ectocervicovaginal lavage. we amplified and sequenced the v3-v4 region of the 16s ribosomal rna (rrna) contents yielding a total of 907,667 high ...201426664918
the consequences of genetic drift for bacterial genome complexity.genetic drift, which is particularly effective within small populations, can shape the size and complexity of genomes by affecting the fixation of deleterious mutations. in bacteria, assessing the contribution of genetic drift to genome evolution is problematic because the usual methods, based on intraspecific polymorphisms, can be thwarted by difficulties in delineating species' boundaries. the increased availability of sequenced bacterial genomes allows application of an alternative estimator ...200919502381
the abcedcba-encoded abc transporter and the virb operon-encoded type iv secretion system of brucella ovis are critical for intracellular trafficking and survival in ovine monocyte-derived macrophages.brucella ovis infection is associated with epididymitis, orchitis and infertility in rams. most of the information available on b. ovis and host cell interaction has been generated using murine macrophages or epithelial cell lines, but the interaction between b. ovis and primary ovine macrophages has not been studied. the aim of this study was to evaluate the role of the b. ovis abcedcba-encoded abc transporter and the virb operon-encoded type iv secretion system (t4ss) during intracellular surv ...201526366863
genomics against flatulence. 200717635535
effects of resource chemistry on the composition and function of stream hyporheic biofilms.fluvial ecosystems process large quantities of dissolved organic matter as it moves from the headwater streams to the sea. in particular, hyporheic sediments are centers of high biogeochemical reactivity due to their elevated residence time and high microbial biomass and activity. however, the interaction between organic matter and microbial dynamics in the hyporheic zone remains poorly understood. we evaluated how variance in resource chemistry affected the microbial community and its associate ...201222347877
bacterial endosymbiosis in a chordate host: long-term co-evolution and conservation of secondary metabolism.intracellular symbiosis is known to be widespread in insects, but there are few described examples in other types of host. these symbionts carry out useful activities such as synthesizing nutrients and conferring resistance against adverse events such as parasitism. such symbionts persist through host speciation events, being passed down through vertical transmission. due to various evolutionary forces, symbionts go through a process of genome reduction, eventually resulting in tiny genomes wher ...201324324632
characterization of species-specific repeats in 613 prokaryotic species.prokaryotes are in general believed to possess small, compactly organized genomes, with repetitive sequences forming only a small part of them. nonetheless, many prokaryotic genomes in fact contain species-specific repeats (>85 bp long genomic sequences with less than 60% identity to other species) as we have previously demonstrated. however, it is not known at present how frequent such species-specific repeats are and what their functional roles in bacterial genomes may be. therefore, we have c ...201222368180
evolutionary diversification and characterization of the eubacterial gene family encoding dxr type ii, an alternative isoprenoid biosynthetic enzyme.isoprenoids constitute a vast family of natural compounds performing diverse and essential functions in all domains of life. in most eubacteria, isoprenoids are synthesized through the methylerythritol 4-phosphate (mep) pathway. the production of mep is usually catalyzed by deoxyxylulose 5-phosphate reductoisomerase (dxr-i) but a few organisms use an alternative dxr-like enzyme (dxr-ii).201324004839
brucella bior regulator defines a complex regulatory mechanism for bacterial biotin metabolism.the enzyme cofactor biotin (vitamin h or b7) is an energetically expensive molecule whose de novo biosynthesis requires 20 atp equivalents. it seems quite likely that diverse mechanisms have evolved to tightly regulate its biosynthesis. unlike the model regulator bira, a bifunctional biotin protein ligase with the capability of repressing the biotin biosynthetic pathway, bior has been recently reported by us as an alternative machinery and a new type of gntr family transcriptional factor that ca ...201323729648
riboregulation in plant-associated α-proteobacteria.the symbiotic α-rhizobia sinorhizobium meliloti, bradyrhizobium japonicum, rhizobium etli and the related plant pathogen agrobacterium tumefaciens are important model organisms for studying plant-microbe interactions. these metabolically versatile soil bacteria are characterized by complex lifestyles and large genomes. here we summarize the recent knowledge on their small non-coding rnas (srnas) including conservation, function, and interaction of the srnas with the rna chaperone hfq. in each of ...201425003187
data integration for dynamic and sustainable systems biology resources: challenges and lessons learned.systems-biology and infectious-disease (host-pathogen-environment) research and development is becoming increasingly dependent on integrating data from diverse and dynamic sources. maintaining integrated resources over long periods of time presents distinct challenges. this review describes experiences and lessons learned from integrating data in two five-year projects focused on pathosystems biology: the pathosystems resource integration center (patric, http://patric.vbi.vt.edu/), with a goal o ...201020491070
brucella canis infection in dogs attended in veterinary clinics from patos, parabaība state, brazil.to determine the frequency of anti-brucella canis antibodies in dogs attended in veterinary clinics from patos, paraíba state, brazil, as well as to identify risk factors and to isolate and identify the agent, 193 dogs were used. agar gel immunodiffusion test (agid) was used to detect b. canis antibodies in sera. isolation of b. canis was carried out in blood and bone marrow from seropositive animals. six animals tested seropositive in agid, resulting in a frequency of 3.11%. b. canis was isolat ...201124031770
yersinia enterocolitica serotype o:9 cultured from swedish sheep showing serologically false-positive reactions for brucella melitensis.in a herd of 20 sheep in sweden, a country where brucellosis has never been diagnosed in sheep or goats, a total of six sheep were found serologically positive to brucella melitensis in two different rounds of sampling. yersinia enterocolitica serotype o:9 could at the time of the second sampling be isolated from four sheep, one of them at the same time serologically positive for b. melitensis. the article describes the case and gives some background information on brucellosis and y. enterocolit ...201223240071
the histidine kinase pdhs controls cell cycle progression of the pathogenic alphaproteobacterium brucella abortus.bacterial differentiation is often associated with the asymmetric localization of regulatory proteins, such as histidine kinases. pdhs is an essential and polarly localized histidine kinase in the pathogenic alphaproteobacterium brucella abortus. after cell division, pdhs is asymmetrically segregated between the two sibling cells, highlighting a differentiation event. however, the function(s) of pdhs in the b. abortus cell cycle remains unknown. we used an original approach, the pentapeptide sca ...201222843843
comparative genomics of early-diverging brucella strains reveals a novel lipopolysaccharide biosynthesis pathway.brucella species are gram-negative bacteria that infect mammals. recently, two unusual strains (brucella inopinata bo1(t) and b. inopinata-like bo2) have been isolated from human patients, and their similarity to some atypical brucellae isolated from australian native rodent species was noted. here we present a phylogenomic analysis of the draft genome sequences of bo1(t) and bo2 and of the australian rodent strains 83-13 and nf2653 that shows that they form two groups well separated from the ot ...201222930339
improved variation calling via an iterative backbone remapping and local assembly method for bacterial genomes.sequencing data analysis remains limiting and problematic, especially for low complexity repeat sequences and transposon elements due to inherent sequencing errors and short sequence read lengths. we have developed a program, reviseq, which uses a hybrid method composed of iterative remapping and local assembly upon a bacterial sequence backbone. application of this method to six brucella suis field isolates compared to the newly revised b. suis 1330 reference genome identified on average 13, 15 ...201222967795
sinorhizobium meliloti exor is the target of periplasmic proteolysis.sinorhizobium meliloti exor regulates the production of succinoglycan and flagella through the exos/chvi two-component regulatory system. exor has been proposed to inhibit the exos sensor through direct interaction in the periplasm. to understand how exor suppression of exos is relieved, which is required for the expression of exos/chvi-regulated symbiosis genes, we characterized wild-type exor and exor95 mutant proteins. in addition to the previously identified precursor and mature forms of exo ...201222636773
comparison of two suspension arrays for simultaneous detection of five biothreat bacterial in powder samples.we have developed novel bio-plex assays for simultaneous detection of bacillus anthracis, yersinia pestis, brucella spp., francisella tularensis, and burkholderia pseudomallei. universal primers were used to amplify highly conserved region located within the 16s rrna amplicon, followed by hybridized to pathogen-specific probes for identification of these five organisms. the other assay is based on multiplex pcr to simultaneously amplify five species-specific pathogen identification-targeted regi ...201222690123
metal acquisition and virulence in brucella.similar to other bacteria, brucella strains require several biologically essential metals for their survival in vitro and in vivo. acquiring sufficient levels of some of these metals, particularly iron, manganese and zinc, is especially challenging in the mammalian host, where sequestration of these micronutrients is a well-documented component of both the innate and acquired immune responses. this review describes the brucella metal transporters that have been shown to play critical roles in th ...201222632611
a comparative genomics screen identifies a sinorhizobium meliloti 1021 sodm-like gene strongly expressed within host plant nodules.we have used the genomic data in the integrated microbial genomes system of the department of energy's joint genome institute to make predictions about rhizobial open reading frames that play a role in nodulation of host plants. the genomic data was screened by searching for orfs conserved in α-proteobacterial rhizobia, but not conserved in closely-related non-nitrogen-fixing α-proteobacteria.201222587634
spontaneous excision of the o-polysaccharide wbka glycosyltranferase gene is a cause of dissociation of smooth to rough brucella colonies.the brucellae are gram-negative pathogens that cause brucellosis, a zoonosis of worldwide importance. the genus brucella includes smooth and rough species that differ in that they carry smooth and rough lipopolysaccharides, respectively. brucella abortus, b. melitensis, and b. suis are typical smooth species. however, these smooth brucellae dissociate into rough mutants devoid of the lipopolysaccharide o-polysaccharide, a major antigen and a virulence determinant encoded in regions wbo (included ...201222328663
vaxjo: a web-based vaccine adjuvant database and its application for analysis of vaccine adjuvants and their uses in vaccine development.vaccine adjuvants are compounds that enhance host immune responses to co-administered antigens in vaccines. vaxjo is a web-based central database and analysis system that curates, stores, and analyzes vaccine adjuvants and their usages in vaccine development. basic information of a vaccine adjuvant stored in vaxjo includes adjuvant name, components, structure, appearance, storage, preparation, function, safety, and vaccines that use this adjuvant. reliable references are curated and cited. bioin ...201222505817
brucella ceti and brucellosis in cetaceans.since the first case of brucellosis detected in a dolphin aborted fetus, an increasing number of brucella ceti isolates has been reported in members of the two suborders of cetaceans: mysticeti and odontoceti. serological surveys have shown that cetacean brucellosis may be distributed worldwide in the oceans. although all b. ceti isolates have been included within the same species, three different groups have been recognized according to their preferred host, bacteriological properties, and dist ...201222919595
analysis of the sos response of vibrio and other bacteria with multiple chromosomes.the sos response is a well-known regulatory network present in most bacteria and aimed at addressing dna damage. it has also been linked extensively to stress-induced mutagenesis, virulence and the emergence and dissemination of antibiotic resistance determinants. recently, the sos response has been shown to regulate the activity of integrases in the chromosomal superintegrons of the vibrionaceae, which encompasses a wide range of pathogenic species harboring multiple chromosomes. here we combin ...201222305460
analyses of brucella pathogenesis, host immunity, and vaccine targets using systems biology and bioinformatics.brucella is a gram-negative, facultative intracellular bacterium that causes zoonotic brucellosis in humans and various animals. out of 10 classified brucella species, b. melitensis, b. abortus, b. suis, and b. canis are pathogenic to humans. in the past decade, the mechanisms of brucella pathogenesis and host immunity have been extensively investigated using the cutting edge systems biology and bioinformatics approaches. this article provides a comprehensive review of the applications of omics ...201222919594
crystal structures of the toll/interleukin-1 receptor (tir) domains from the brucella protein tcpb and host adaptor tirap reveal mechanisms of molecular mimicry.the toll/il-1 receptor (tir) domains are crucial innate immune signaling modules. microbial tir domain-containing proteins inhibit toll-like receptor (tlr) signaling through molecular mimicry. the tir domain-containing protein tcpb from brucella inhibits tlr signaling through interaction with host adaptor proteins tirap/mal and myd88. to characterize the microbial mimicry of host proteins, we have determined the x-ray crystal structures of the tir domains from the brucella protein tcpb and the h ...201324275656
crystal structures of the toll/interleukin-1 receptor (tir) domains from the brucella protein tcpb and host adaptor tirap reveal mechanisms of molecular mimicry.the toll/il-1 receptor (tir) domains are crucial innate immune signaling modules. microbial tir domain-containing proteins inhibit toll-like receptor (tlr) signaling through molecular mimicry. the tir domain-containing protein tcpb from brucella inhibits tlr signaling through interaction with host adaptor proteins tirap/mal and myd88. to characterize the microbial mimicry of host proteins, we have determined the x-ray crystal structures of the tir domains from the brucella protein tcpb and the h ...201324275656
lon mutant of brucella abortus induces tumor necrosis factor-alpha in murine j774.a1 macrophage.the objective of this study was to isolate a brucella lon mutant and to analyze the cytokine response of b. lon mutant during macrophage infection.201324524018
toxoplasmosis, leptospirosis and brucellosis in stray dogs housed at the shelter in umuarama municipality, paraná, brazil.leptospirosis, toxoplasmosis and brucellosis are diseases with worldwide distribution. among stray dogs, these zoonoses are facilitated by direct contact with other animal species, by the habit of scavenging garbage and hunting in search of food, drinking standing water, smelling other animals' urine, licking female genitalia and the sexual act itself. the objective of this study was to detect antibodies anti-toxoplasma gondii, anti-leptospira spp., anti-brucella canis and anti-brucella abortus ...201324066949
limitations of the bp26 protein-based indirect enzyme-linked immunosorbent assay for diagnosis of brucellosis.brucellosis is a serious zoonosis that occurs worldwide, and its diagnosis is typically based on the detection of antibodies against brucella lipopolysaccharide (lps). however, the specificity of the lps-based test is compromised by cross-reactivity with escherichia coli o157:h7 and yersinia enterocolitica o:9. also, diagnosis based on the lps test cannot differentiate between vaccinated and infected individuals. the detection of the 26-kda cytosoluble protein (bp26) antibody is considered an al ...201323863503
comparative genomic analysis of brucella melitensis vaccine strain m5 provides insights into virulence attenuation.the brucella melitensis vaccine strain m5 is widely used to prevent and control brucellosis in animals. in this study, we determined the whole-genome sequence of m5, and conducted a comprehensive comparative analysis against the whole-genome sequence of the virulent strain 16 m and other reference strains. this analysis revealed 11 regions of deletion (rds) and 2 regions of insertion (ris) within the m5 genome. among these regions, the sequences encompassed in 5 rds and 1 ri showed consistent va ...201323967122
development and comparative evaluation of a plate enzyme-linked immunosorbent assay based on recombinant outer membrane antigens omp28 and omp31 for diagnosis of human brucellosis.brucellosis is an important zoonotic infectious disease of humans and livestock with worldwide distribution and is caused by bacteria of the genus brucella. the diagnosis of brucellosis always requires laboratory confirmation by either isolation of pathogens or detection of specific antibodies. the conventional serological tests available for the diagnosis of brucellosis are less specific and show cross-reactivity with other closely related organisms. these tests also necessitate the handling of ...201323761658
bartonella and brucella--weapons and strategies for stealth attack.bartonella spp. and brucella spp. are closely related α-proteobacterial pathogens that by distinct stealth-attack strategies cause chronic infections in mammals including humans. human infections manifest by a broad spectrum of clinical symptoms, ranging from mild to fatal disease. both pathogens establish intracellular replication niches and subvert diverse pathways of the host's immune system. several virulence factors allow them to adhere to, invade, proliferate, and persist within various ho ...201323906880
rapid quantitative detection of brucella melitensis by a label-free impedance immunosensor based on a gold nanoparticle-modified screen-printed carbon electrode.a rapid and simple method for quantitative monitoring of brucella melitensis using electrochemical impedance spectroscopy (eis) is reported for the first time. the label-free immunosensors were fabricated by immobilizing brucella melitensis antibody on the surface of gold nanoparticle-modified screen-printed carbon electrodes (gnp-spces). cyclic voltammetry (cv) and eis were used to characterize the brucella melitensis antigen interaction on the surface of gnp-spces with antibody. a general elec ...201323881126
host-brucella interactions and the brucella genome as tools for subunit antigen discovery and immunization against brucellosis.vaccination is the most important approach to counteract infectious diseases. thus, the development of new and improved vaccines for existing, emerging, and re-emerging diseases is an area of great interest to the scientific community and general public. traditional approaches to subunit antigen discovery and vaccine development lack consideration for the critical aspects of public safety and activation of relevant protective host immunity. the availability of genomic sequences for pathogenic br ...201323720712
molecular mechanisms for the subversion of myd88 signaling by tcpc from virulent uropathogenic escherichia coli.the toll/il-1 receptor (tir) domains are crucial signaling modules during innate immune responses involving the toll-like receptors (tlrs) and il-1 receptor (il-1r). myeloid differential factor 88 (myd88) is a central tir domain-containing adapter molecule responsible for nearly all tlr-mediated signaling and is targeted by a tir domain-containing protein c (tcpc) from virulent uropathogenic escherichia coli, a common human pathogen. the mechanism of such molecular antagonism has remained elusiv ...201323569230
a lysozyme-like protein in brucella abortus is involved in the early stages of intracellular replication.secretion of proteins in gram-negative bacteria is a high-energy-consuming process that requires translocation across two membranes and a periplasmic space composed of a mesh-like layer, the peptidoglycan. to achieve this, bacteria have evolved complex secretion systems that cross these barriers, and in many cases there are specific peptidoglycanases that degrade the peptidoglycan to allow the proper assembly of the secretion machinery. we describe here the identification and characterization of ...201323319555
the predicted abc transporter abcedcba is required for type iv secretion system expression and lysosomal evasion by brucella ovis.brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described brucella species that is not zoonotic. previous work showed that a b. ovis mutant lacking a species-specific abc transporter (δabcba) was attenuated in mice and was unable to survive in macrophages. the aim of this study was to evaluate the role of this abc transporter during intracellular survival of b. ovis. in hela cells, b. ovis wt was able to survive and replicate at later time point (48 h ...201425474545
characterization and evaluation of an arbitrary primed polymerase chain reaction (pcr) product for the specific detection of brucella species.laboratory detection of brucella is based largely on bacterial isolation and phenotypic characterization. these methods are lengthy and labor-intensive and have been associated with a heightened risk of laboratory-acquired infection. antibody based indirect detection methods also suffer from limitations in proper diagnosis of the organism. to overcome these problems, nucleic acid amplification has been explored for rapid detection and confirmation of the presence of brucella spp. pcr-based diagn ...201425737656
characterization and evaluation of an arbitrary primed polymerase chain reaction (pcr) product for the specific detection of brucella species.laboratory detection of brucella is based largely on bacterial isolation and phenotypic characterization. these methods are lengthy and labor-intensive and have been associated with a heightened risk of laboratory-acquired infection. antibody based indirect detection methods also suffer from limitations in proper diagnosis of the organism. to overcome these problems, nucleic acid amplification has been explored for rapid detection and confirmation of the presence of brucella spp. pcr-based diagn ...201425737656
brucella ceti infection in dolphins from the western mediterranean sea.brucella ceti infections have been increasingly reported in cetaceans. brucellosis in these animals is associated with meningoencephalitis, abortion, discospondylitis', subcutaneous abscesses, endometritis and other pathological conditions b. ceti infections have been frequently described in dolphins from both, the atlantic and pacific oceans. in the mediterranean sea, only two reports have been made: one from the italian tyrrhenian sea and the other from the adriatic sea.201425224818
a novel omp25-binding peptide screened by phage display can inhibit brucella abortus 2308 infection in vitro and in vivo.brucellosis is a globally distributed zoonotic disease affecting animals and humans, and current antibiotic and vaccine strategies are not optimal. the surface-exposed protein omp25 is involved in brucella virulence and plays an important role in brucella pathogenesis during infection, suggesting that omp25 could be a useful target for selecting potential therapeutic molecules to inhibit brucella pathogenesis. in this study, we identified, we believe for the first time, peptides that bind specif ...201424722798
retrospective and prospective perspectives on zoonotic brucellosis.members of the genus brucella are pathogenic bacteria exceedingly well adapted to their hosts. the bacterium is transmitted by direct contact within the same host species or accidentally to secondary hosts, such as humans. human brucellosis is strongly linked to the management of domesticated animals and ingestion of their products. since the domestication of ungulates and dogs in the fertile crescent and asia in 12000 and 33000 ya, respectively, a steady supply of well adapted emergent brucella ...201424860561
evaluation of three formulations of culture media for isolation of brucella spp. regarding their ability to inhibit the growth of contaminating organisms.three culture media (brucella agar, farrell medium, and cita) were compared for their effectiveness in inhibiting contamination and for isolating brucella spp. one hundred lymph nodes from pigs (n = 50) and wild boars (n = 50) with lymphadenitis were collected in slaughterhouses in the state of são paulo and were assessed on these three selective media for brucella spp. all of the samples were negative for brucella spp. on the three culture media. on the agar medium, fungal (70 plates) and gram- ...201424949466
comparative phylogenomics and evolution of the brucellae reveal a path to virulence.brucella species include important zoonotic pathogens that have a substantial impact on both agriculture and human health throughout the world. brucellae are thought of as "stealth pathogens" that escape recognition by the host innate immune response, modulate the acquired immune response, and evade intracellular destruction. we analyzed the genome sequences of members of the family brucellaceae to assess its evolutionary history from likely free-living soil-based progenitors into highly success ...201424336939
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