Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
assessing the evolutionary rate of positional orthologous genes in prokaryotes using synteny data.comparison of completely sequenced microbial genomes has revealed how fluid these genomes are. detecting synteny blocks requires reliable methods to determining the orthologs among the whole set of homologs detected by exhaustive comparisons between each pair of completely sequenced genomes. this is a complex and difficult problem in the field of comparative genomics but will help to better understand the way prokaryotic genomes are evolving.200718047665
transcriptional regulatory network discovery via multiple method integration: application to e. coli k12.transcriptional regulatory network (trn) discovery from one method (e.g. microarray analysis, gene ontology, phylogenic similarity) does not seem feasible due to lack of sufficient information, resulting in the construction of spurious or incomplete trns. we develop a methodology, trnd, that integrates a preliminary trn, microarray data, gene ontology and phylogenic similarity to accurately discover trns and apply the method to e. coli k12. the approach can easily be extended to include other me ...200717397539
the flik protein and flagellar hook-length control.the bacterial flagellum is a highly complex prokaryotic organelle. it is the motor that drives bacterial motility, and despite the large amount of energy required to make and operate flagella, motile organisms have a strong adaptive advantage. flagellar biogenesis is both complex and highly coordinated and it typically involves at least three two-component systems. part of the flagellum is a type iii secretion system, and it is via this structure that flagellar components are exported. the assem ...200717456739
identification of genes encoding trna modification enzymes by comparative genomics.as the molecular adapters between codons and amino acids, transfer-rnas are pivotal molecules of the genetic code. the coding properties of a trna molecule do not reside only in its primary sequence. posttranscriptional nucleoside modifications, particularly in the anticodon loop, can modify cognate codon recognition, affect aminoacylation properties, or stabilize the codon-anticodon wobble base pairing to prevent ribosomal frameshifting. despite a wealth of biophysical and structural knowledge ...200717673083
characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering.sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ...200717163981
characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering.sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ...200717163981
purification and characterization of arylmalonate decarboxylase from achromobacter sp. ku1311.we have isolated, purified and characterized arylmalonate decarboxylase (amdase; ec 4.1.1.76). this is an unique enzyme that gives optically pure arylpropionates from the corresponding arylmalonates. recently, we have screened similar enzyme producers from soil samples and succeeded in isolating achromobacter sp. ku1311. the gene encoding the enzyme was cloned and sequenced. the amdase gene consists of 720 nucleotides, which specifies a 240 amino acid protein with a relative molecular mass of 24 ...200718023797
during infection of epithelial cells salmonella enterica serovar typhimurium undergoes a time-dependent transcriptional adaptation that results in simultaneous expression of three type 3 secretion systems.the biogenesis of the salmonella-containing vacuole within mammalian cells has been intensively studied over recent years. however, the ability of salmonella to sense and adapt to the intracellular environment of different types of host cells has received much less attention. to address this issue, we report the transcriptome of salmonella enterica serovar typhimurium sl1344 within epithelial cells and show comparisons with salmonella gene expression inside macrophages. we report that s. typhimu ...200818031307
real-time pcr assays of single-nucleotide polymorphisms defining the major brucella clades.members of the genus brucella are known worldwide as pathogens of wildlife and livestock and are the most common organisms of zoonotic infection in humans. in general, brucellae exhibit a range of host specificity in animals that has led to the identification of at least seven brucella species. the genomes of the various brucella species are highly conserved, which makes the differentiation of species highly challenging. however, we found single-nucleotide polymorphisms (snps) in housekeeping an ...200818032628
real-time pcr assays of single-nucleotide polymorphisms defining the major brucella clades.members of the genus brucella are known worldwide as pathogens of wildlife and livestock and are the most common organisms of zoonotic infection in humans. in general, brucellae exhibit a range of host specificity in animals that has led to the identification of at least seven brucella species. the genomes of the various brucella species are highly conserved, which makes the differentiation of species highly challenging. however, we found single-nucleotide polymorphisms (snps) in housekeeping an ...200818032628
disposition kinetics and urinary excretion of ciprofloxacin in goats following single intravenous administration.we evaluated the pharmacokinetics of ciprofloxacin in serum (n = 6) and urine (n = 4) in goats following a single intravenous administration of 4 mg/kg body weight. the serum concentration-time curves of ciprofloxacin were best fitted by a two-compartment open model. the drug was detected in goat serum up to 12 h. the elimination rate constant (beta) and elimination half-life (t1/2beta) were 0.446 +/- 0.04 h(-1) and 1.630 +/- 0.17 h, espectively. the apparent volume of distribution at steady sta ...200818716443
the guinea pig as a model of infectious diseases.the words 'guinea pig' are synonymous with scientific experimentation, but much less is known about this species than many other laboratory animals. this animal model has been used for approximately 200 y and was the first to be used in the study of infectious diseases such as tuberculosis and diphtheria. today the guinea pig is used as a model for a number of infectious bacterial diseases, including pulmonary, sexually transmitted, ocular and aural, gastrointestinal, and other infections that t ...200818724774
burkholderia thailandensis as a model system for the study of the virulence-associated type iii secretion system of burkholderia pseudomallei.burkholderia pseudomallei is a bacterial pathogen that causes a broad spectrum of clinical symptoms collectively known as melioidosis. since it can be acquired by inhalation and is difficult to eradicate due to its resistance to a wide group of antibiotics and capacity for latency, work with b. pseudomallei requires a biosafety level 3 (bsl-3) containment facility. the bsa (burkholderia secretion apparatus)-encoded type iii secretion system (ttss) has been shown to be required for its full virul ...200818779342
detection of respiratory pathogens in air samples from acutely infected pigs.pathogens causing significant respiratory disease in growing pigs include porcine reproductive and respiratory syndrome virus, porcine circovirus 2, swine influenza virus, porcine respiratory coronavirus, mycoplasma hyopneumoniae, and bordetella bronchiseptica. the objective of this research was to characterize the respiratory excretion of these pathogens by acutely infected pigs. pigs were inoculated under experimental conditions with 1 pathogen. samples were collected from the upper respirator ...200818783027
bordetella pertussis isolates in finland: serotype and fimbrial expression.bordetella pertussis causes whooping cough or pertussis in humans. it produces several virulence factors, of which the fimbriae are considered adhesins and elicit immune responses in the host. b. pertussis has three distinct serotypes fim2, fim3 or fim2,3. generally, b. pertussis fim2 strains predominate in unvaccinated populations, whereas fim3 strains are often isolated in vaccinated populations. in finland, pertussis vaccination was introduced in 1952. the whole-cell vaccine contained two str ...200818816412
the missing link: bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic bordetellae.bordetella petrii is the only environmental species hitherto found among the otherwise host-restricted and pathogenic members of the genus bordetella. phylogenetically, it connects the pathogenic bordetellae and environmental bacteria of the genera achromobacter and alcaligenes, which are opportunistic pathogens. b. petrii strains have been isolated from very different environmental niches, including river sediment, polluted soil, marine sponges and a grass root. recently, clinical isolates asso ...200818826580
single-dose, virus-vectored vaccine protection against yersinia pestis challenge: cd4+ cells are required at the time of challenge for optimal protection.we have developed an experimental recombinant vesicular stomatitis virus (vsv) vectored plague vaccine expressing a secreted form of yersinia pestis low calcium response protein v (lcrv) from the first position of the vsv genome. this vector, given intramuscularly in a single dose, induced high-level antibody titers to lcrv and gave 90-100% protection against pneumonic plague challenge in mice. this single-dose protection was significantly better than that generated by vsv expressing the non-sec ...200818832004
diversity of incp-9 plasmids of pseudomonas.incp-9 plasmids are important vehicles for degradation and resistance genes that contribute to the adaptability of pseudomonas species in a variety of natural habitats. the three completely sequenced incp-9 plasmids, pww0, pdtg1 and nah7, show extensive homology in replication, partitioning and transfer loci (an approximately 25 kb region) and to a lesser extent in the remaining backbone segments. we used pcr, dna sequencing, hybridization and phylogenetic analyses to investigate the genetic div ...200818832300
iterative reconstruction of a global metabolic model of acinetobacter baylyi adp1 using high-throughput growth phenotype and gene essentiality data.genome-scale metabolic models are powerful tools to study global properties of metabolic networks. they provide a way to integrate various types of biological information in a single framework, providing a structured representation of available knowledge on the metabolism of the respective species.200818840283
antibiograms of pathogenic bacteria isolated from laboratory rabbits in ibadan, nigeria.antibiotic sensitivity patterns of 21 bacterial isolates from some clinically ill new zealand rabbits were evaluated against 12 commonly used antibiotics by the kirby-bauer disk-diffusion sensitivity testing method. the 21 isolates consisted of six bordetella bronchiseptica, eight pasteurella multocida, four staphylococcus aureus and three pseudomonas alcaligenes that were associated with snuffles, pneumonia, otitis media, genital infections and conjunctivitis in these groups of caged rabbits. t ...200818840619
porcine reproductive and respiratory syndrome virus (prrsv) in gb pig herds: farm characteristics associated with heterogeneity in seroprevalence.the between- and within-herd variability of porcine reproductive and respiratory syndrome virus (prrsv) antibodies were investigated in a cross-sectional study of 103 british pig herds conducted 2003-2004. fifty pigs from each farm were tested for anti-prrsv antibodies using elisa. a binomial logistic model was used to investigate management risks for farms with and without pigs with prrsv antibodies and multilevel statistical models were used to investigate variability in pigs' log elisa irpc ( ...200819040719
modulation of the nf-kappab pathway by bordetella pertussis filamentous hemagglutinin.filamentous hemagglutinin (fha) is a cell-associated and secreted adhesin produced by bordetella pertussis with pro-apoptotic and pro-inflammatory activity in host cells. given the importance of the nf-kappab transcription factor family in these host cell responses, we examined the effect of fha on nf-kappab activation in macrophages and bronchial epithelial cells, both of which are relevant cell types during natural infection.200819043589
efficacy and safety of five injectable anesthetic regimens for chronic blood collection from the anterior vena cava of guinea pigs.despite several published methods of inducing surgical anesthesia in guinea pigs, viable methods of anesthesia for blood collection from the vena cava are inadequate. we compared 5 anesthesia regimens and their efficacy in inducing anesthesia for blood sampling in guinea pigs: ketamine-xylazine (30 and 2.5 mg/kg) administered subcutaneously, intramuscularly, or intraperitoneally; pentobarbital (37 mg/kg) administered intraperitoneally; and medetomidine (0.5 mg/kg) administered intramuscularly. p ...200819049255
demonstration of 1-year duration of immunity for attenuated bordetella bronchiseptica vaccines in dogs.three groups of healthy dogs with low antibody titers to bordetella bronchiseptica (bb), canine parainfluenza virus (cpi), and canine adenovirus type 2 (cav-2) were used in this study. one group was vaccinated with a single dose of monovalent attenuated bb vaccine and one group with a trivalent vaccine containing attenuated bb, cpi, and cav-2; dogs were vaccinated intranasally with a single dose of the respective vaccines. the third group served as unvaccinated controls. all vaccinated dogs subs ...200819177330
using mahalanobis distance to compare genomic signatures between bacterial plasmids and chromosomes.plasmids are ubiquitous mobile elements that serve as a pool of many host beneficial traits such as antibiotic resistance in bacterial communities. to understand the importance of plasmids in horizontal gene transfer, we need to gain insight into the 'evolutionary history' of these plasmids, i.e. the range of hosts in which they have evolved. since extensive data support the proposal that foreign dna acquires the host's nucleotide composition during long-term residence, comparison of nucleotide ...200818953039
study of a bordetella hinzii isolate from a laboratory mouse.bordetella hinzii isolated from the trachea and lungs of a laboratory mouse with a respiratory infection was identified based on its phenotypic and genetic traits. the mouse showed sneezing with a chattering sound but without nasal discharge, and histopathologic examination revealed rhinitis, tracheitis, and bronchopneumonia. the isolate was a gram-negative, oxidase- and catalase-positive, short rod-shaped organism that produced alkali from malonate. the results of biochemical identification, an ...200819004369
hiv/aids education: still an important issue for veterinarians.human immunodeficiency virus (hiv)/acquired immunodeficiency syndrome (aids) is a significant cause of immunosuppression that puts infected individuals at higher risk for developing severe complications from zoonotic infections and other animal-related hazards. the number of people living with hiv grows each year, assuring that veterinary practitioners will have clients and/or employees who are afflicted with hiv/aids. veterinarians need to better understand hiv/aids for many reasons: to dispel ...200819006969
comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides.growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (aps). these compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. studies focused on the systematic characterization of aps are hampered by the lack of standard guidelines for testing these compounds. we investigated whether the information provided by methods commonly used for the biologic ...200819014450
the genome sequence of the fish pathogen aliivibrio salmonicida strain lfi1238 shows extensive evidence of gene decay.the fish pathogen aliivibrio salmonicida is the causative agent of cold-water vibriosis in marine aquaculture. the gram-negative bacterium causes tissue degradation, hemolysis and sepsis in vivo.200819099551
the petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.the petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. the neonatal pet/pet rats had a low body weight and small thymus and testis. during the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. the pet/pet rats exhibited proportional dwarfism, and their ...200819149412
diversity-generating retroelement homing regenerates target sequences for repeated rounds of codon rewriting and protein diversification.diversity-generating retroelements (dgrs) introduce vast amounts of sequence diversity into target genes. during mutagenic homing, adenine residues are converted to random nucleotides in a unidirectional, reverse transcriptase-dependent transposition process from a donor template repeat (tr) to a recipient variable repeat (vr). using a bordetella bacteriophage dgr as a model, we demonstrate that homing occurs through a tr-containing rna intermediate and is reca independent. marker transfer studi ...200818922465
complete genome sequence and comparative analysis of the wild-type commensal escherichia coli strain se11 isolated from a healthy adult.we sequenced and analyzed the genome of a commensal escherichia coli (e. coli) strain se11 (o152:h28) recently isolated from feces of a healthy adult and classified into e. coli phylogenetic group b1. se11 harbored a 4.8 mb chromosome encoding 4679 protein-coding genes and six plasmids encoding 323 protein-coding genes. none of the se11 genes had sequence similarity to known genes encoding phage- and plasmid-borne virulence factors found in pathogenic e. coli strains. the comparative genome anal ...200818931093
boolean network simulations for life scientists.modern life sciences research increasingly relies on computational solutions, from large scale data analyses to theoretical modeling. within the theoretical models boolean networks occupy an increasing role as they are eminently suited at mapping biological observations and hypotheses into a mathematical formalism. the conceptual underpinnings of boolean modeling are very accessible even without a background in quantitative sciences, yet it allows life scientists to describe and explore a wide r ...200819014577
detection of mycoplasma hyopneumoniae by polymerase chain reaction in swine presenting respiratory problems.since mycoplasma hyopneumoniae isolation in appropriate media is a difficult task and impractical for daily routine diagnostics, nested-pcr (n-pcr) techniques are currently used to improve the direct diagnostic sensitivity of swine enzootic pneumonia. in a first experiment, this paper describes a n-pcr technique optimization based on three variables: different sampling sites, sample transport media, and dna extraction methods, using eight pigs. based on the optimization results, a second experim ...200824031248
a new pheromone trail-based genetic algorithm for comparative genome assembly.gap closing is considered one of the most challenging and time-consuming tasks in bacterial genome sequencing projects, especially with the emergence of new sequencing technologies, such as pyrosequencing, which may result in large amounts of data without the benefit of large insert libraries for contig scaffolding. we propose a novel algorithm to align contigs with more than one reference genome at a time. this approach can successfully overcome the limitations of low degrees of conserved gene ...200818445633
bacterial heme-transport proteins and their heme-coordination modes.efficient iron acquisition is critical for an invading microbe's survival and virulence. most of the iron in mammals is incorporated into heme, which can be plundered by certain bacterial pathogens as a nutritional iron source. utilization of exogenous heme by bacteria involves the binding of heme or hemoproteins to the cell surface receptors, followed by the transport of heme into cells. once taken into the cytosol, heme is presented to heme oxygenases where the tetrapyrrole ring is cleaved in ...200818977196
bacterial heme-transport proteins and their heme-coordination modes.efficient iron acquisition is critical for an invading microbe's survival and virulence. most of the iron in mammals is incorporated into heme, which can be plundered by certain bacterial pathogens as a nutritional iron source. utilization of exogenous heme by bacteria involves the binding of heme or hemoproteins to the cell surface receptors, followed by the transport of heme into cells. once taken into the cytosol, heme is presented to heme oxygenases where the tetrapyrrole ring is cleaved in ...200818977196
on the physiology and pathophysiology of antimicrobial peptides.antimicrobial peptides (amp) are a heterogeneous group of molecules involved in the nonspecific immune responses of a variety of organisms ranging from prokaryotes to mammals, including humans. amp have various physical and biological properties, yet the most common feature is their antimicrobial effect. the majority of amp disrupt the integrity of microbial cells by 1 of 3 known mechanisms--the barrel-stave pore model, the thoroidal pore model, or the carpet model. results of growing numbers of ...200819015736
on the physiology and pathophysiology of antimicrobial peptides.antimicrobial peptides (amp) are a heterogeneous group of molecules involved in the nonspecific immune responses of a variety of organisms ranging from prokaryotes to mammals, including humans. amp have various physical and biological properties, yet the most common feature is their antimicrobial effect. the majority of amp disrupt the integrity of microbial cells by 1 of 3 known mechanisms--the barrel-stave pore model, the thoroidal pore model, or the carpet model. results of growing numbers of ...200819015736
minimum contradiction matrices in whole genome phylogenies.minimum contradiction matrices are a useful complement to distance-based phylogenies. a minimum contradiction matrix represents phylogenetic information under the form of an ordered distance matrix y(i) (,) (j) (n). a matrix element corresponds to the distance from a reference vertex n to the path (i, j). for an x-tree or a split network, the minimum contradiction matrix is a robinson matrix. it therefore fulfills all the inequalities defining perfect order: y(i) (,) (j) (n) >or= y(i) (,) (k) (n ...200819204821
host defense peptides in the oral cavity and the lung: similarities and differences.peptides with broad-spectrum antimicrobial activity are found in the mucosal surfaces at many sites in the body, including the airway, the oral cavity, and the digestive tract. based on their in vitro antimicrobial and other immunomodulatory activities, these host defense peptides have been proposed to play an important role in the innate defense against pathogenic microbial colonization. the genes that encode these peptides are up-regulated by pathogens, further supporting their role in innate ...200818809744
neutrophil recruitment to the lungs during bacterial pneumonia. 200819015252
neutrophil recruitment to the lungs during bacterial pneumonia. 200819015252
white tide. 200825949289
white tide. 200825949289
systematic identification of stem-loop containing sequence families in bacterial genomes.analysis of non-coding sequences in several bacterial genomes brought to the identification of families of repeated sequences, able to fold as secondary structures. these sequences have often been claimed to be transcribed and fulfill a functional role. a previous systematic analysis of a representative set of 40 bacterial genomes produced a large collection of sequences, potentially able to fold as stem-loop structures (sls). computational analysis of these sequences was carried out by searchin ...200818201379
genome-wide survey of prokaryotic serine proteases: analysis of distribution and domain architectures of five serine protease families in prokaryotes.serine proteases are one of the most abundant groups of proteolytic enzymes found in all the kingdoms of life. while studies have established significant roles for many prokaryotic serine proteases in several physiological processes, such as those associated with metabolism, cell signalling, defense response and development, functional associations for a large number of prokaryotic serine proteases are relatively unknown. current analysis is aimed at understanding the distribution and probable b ...200819019219
estimating the fraction of non-coding rnas in mammalian transcriptomes.recent studies of mammalian transcriptomes have identified numerous rna transcripts that do not code for proteins; their identity, however, is largely unknown. here we explore an approach based on sequence randomness patterns to discern different rna classes. the relative z-score we use helps identify the known ncrna class from the genome, intergene and intron classes. this leads us to a fractional ncrna measure of putative ncrna datasets which we model as a mixture of genuine ncrnas and other t ...200819812767
pulmonary bacterial pathogens in cystic fibrosis patients and antibiotic therapy: a tool for the health workers.cystic fibrosis is the most common and best known genetic disease involving a defect in transepithelial cl- transport by mutations in the cf gene on chromosome 7, which codes for the cystic fibrosis transmembrane conductance regulator protein (cftr). the most serious symptoms are observed in the lungs, augmenting the risk of bacterial infection. the objective of this review was to describe the bacterial pathogens colonizing patients with cystic fibrosis. a systematic search was conducted using t ...200818992146
assessment of gut bacteria for a paratransgenic approach to control dermolepida albohirtum larvae.bacteria from the hindguts of dermolepida albohirtum larvae were assessed for their potential to be used in paratransgenic strategies that target scarab pests of sugarcane. bacteria isolated in pure culture from the hindguts of d. albohirtum larvae were from the proteobacteria, firmicutes, and actinobacteria phyla and matched closely with taxa from intestinal and rhizosphere environments. however, these isolates were not the most common gut-associated bacteria identified in denaturing gradient g ...200818456847
molecular genetic basis of ribotyping.nearly 2,000 ribotyping-based studies exist, ranging from epidemiology to phylogeny and taxonomy. none precisely reveals the molecular genetic basis, with many incorrectly attributing detected polymorphisms to rrna gene sequences. based on in silico genomics, we demonstrate that ribotype polymorphisms result from sequence variability in neutral housekeeping genes flanking rrna operons, with rrna gene sequences serving solely as conserved, flank-linked tags. we also reveal that from such an infor ...200818400796
multiplex pcr that can distinguish between immunologically cross- reactive serovar 3, 6, and 8 actinobacillus pleuropneumoniae strains.we describe a highly sensitive and specific multiplex pcr, based on capsular loci and the species specific apxiv gene, that unequivocally differentiates serovar 3, 6, and 8 actinobacillus pleuropneumoniae strains that are cross-reactive in conventional immunological tests.200818094137
multiplex pcr that can distinguish between immunologically cross- reactive serovar 3, 6, and 8 actinobacillus pleuropneumoniae strains.we describe a highly sensitive and specific multiplex pcr, based on capsular loci and the species specific apxiv gene, that unequivocally differentiates serovar 3, 6, and 8 actinobacillus pleuropneumoniae strains that are cross-reactive in conventional immunological tests.200818094137
the arac-like transcriptional regulator dhbr is required for maximum expression of the 2,3-dihydroxybenzoic acid biosynthesis genes in brucella abortus 2308 in response to iron deprivation.phenotypic evaluation of isogenic mutants derived from brucella abortus 2308 indicates that the alcr homolog dhbr (2,3-dihydroxybenzoic acid [2,3-dhba] biosynthesis regulator) modulates the expression of the genes involved in 2,3-dhba production, employing 2,3-dhba or brucebactin as a coinducer.200818156262
the arac-like transcriptional regulator dhbr is required for maximum expression of the 2,3-dihydroxybenzoic acid biosynthesis genes in brucella abortus 2308 in response to iron deprivation.phenotypic evaluation of isogenic mutants derived from brucella abortus 2308 indicates that the alcr homolog dhbr (2,3-dihydroxybenzoic acid [2,3-dhba] biosynthesis regulator) modulates the expression of the genes involved in 2,3-dhba production, employing 2,3-dhba or brucebactin as a coinducer.200818156262
application of intact cell-based nfat-beta-lactamase reporter assay for pasteurella multocida toxin-mediated activation of calcium signaling pathway.pasteurella multocida toxin (pmt) stimulates and subsequently uncouples phospholipase c beta1 (plcbeta1) signal transduction through its selective action on the alpha subunit of the gq-protein. here, we describe the application of an nfat-beta-lactamase reporter assay as a functional readout for pmt-induced activation of the gq-protein-coupled plcbeta1-ip(3)-ca(2+) signaling pathway. use of the nfat-beta-lactamase reporter assay with a cell-permeable fluorogenic substrate provides high sensitivi ...200818190943
application of intact cell-based nfat-beta-lactamase reporter assay for pasteurella multocida toxin-mediated activation of calcium signaling pathway.pasteurella multocida toxin (pmt) stimulates and subsequently uncouples phospholipase c beta1 (plcbeta1) signal transduction through its selective action on the alpha subunit of the gq-protein. here, we describe the application of an nfat-beta-lactamase reporter assay as a functional readout for pmt-induced activation of the gq-protein-coupled plcbeta1-ip(3)-ca(2+) signaling pathway. use of the nfat-beta-lactamase reporter assay with a cell-permeable fluorogenic substrate provides high sensitivi ...200818190943
bordetella pertussis expresses a functional type iii secretion system that subverts protective innate and adaptive immune responses.certain bacteria use a type iii secretion system (ttss) to deliver effector proteins that interfere with cell function into host cells. while transcription of genes encoding ttss components has been demonstrated, studies to date have failed to identify ttss effector proteins in bordetella pertussis. here we present the first evidence of a functionally active ttss in b. pertussis. three known ttss effectors, bsp22, bopn, and bopd, were identified as ttss substrates in b. pertussis 12743. we found ...200818195025
utilization of lactoferrin-bound and transferrin-bound iron by campylobacter jejuni.campylobacter jejuni nctc 11168 was capable of growth to levels comparable with feso4 in defined iron-limited medium (minimal essential medium alpha [memalpha]) containing ferrilactoferrin, ferritransferrin, or ferri-ovotransferrin. iron was internalized in a contact-dependent manner, with 94% of cell-associated radioactivity from either 55fe-loaded transferrin or lactoferrin associated with the soluble cell fraction. partitioning the iron source away from bacteria significantly decreased cellul ...200818203832
development of bioluminescent salmonella strains for use in food safety.salmonella can reside in healthy animals without the manifestation of any adverse effects on the carrier. if raw products of animal origin are not handled properly during processing or cooked to a proper temperature during preparation, salmonellosis can occur. in this research, we developed bioluminescent salmonella strains that can be used for real-time monitoring of the pathogen's growth on food products. to accomplish this, twelve salmonella strains from the broiler production continuum were ...200818211715
demonstration of is711 transposition in brucella ovis and brucella pinnipedialis.the brucella genome contains an insertion sequence (is) element called is711 or is6501, which is specific to the genus. the copy number of is711 varies in the genome of the different brucella species, ranging from 7 in b. abortus, b. melitensis and b. suis to more than 30 in b. ovis and in brucella strains isolated from marine mammals. at present, there is no experimental evidence of transposition of is711, but the occurrence of this element with a high copy number in some species, and the isola ...200818218072
the potential of mannosylated chitosan microspheres to target macrophage mannose receptors in an adjuvant-delivery system for intranasal immunization.a vaccine delivery system based on mannosylated chitosan microspheres (mcms) was studied in vitro and in vivo. bordetella bronchiseptica antigens containing dermonecrotoxin (bbd) were loaded in mcms or chitosan microspheres (cms). fluorescence confocal microscopy indicated that bbd-loaded mcms (bbd-mcms) bound with mannose receptors on murine macrophages (raw264.7 cells). in vitro experiments using macrophages demonstrated that bbd-mcms had more effective immune-stimulating activity than bbd-loa ...200818221992
comparative genomics and an insect model rapidly identify novel virulence genes of burkholderia mallei.burkholderia pseudomallei and its host-adapted deletion clone burkholderia mallei cause the potentially fatal human diseases melioidosis and glanders, respectively. the antibiotic resistance profile and ability to infect via aerosol of these organisms and the absence of protective vaccines have led to their classification as major biothreats and select agents. although documented infections by these bacteria date back over 100 years, relatively little is known about their virulence and pathogeni ...200818223084
active-site mobility revealed by the crystal structure of arylmalonate decarboxylase from bordetella bronchiseptica.arylmalonate decarboxylase (amdase) from bordetella bronchiseptica catalyzes the enantioselective decarboxylation of arylmethylmalonates without the need for an organic cofactor or metal ion. the decarboxylation reaction is of interest for the synthesis of fine chemicals. as basis for an analysis of the catalytic mechanism of amdase and for a rational enzyme design, we determined the x-ray structure of the enzyme up to 1.9 a resolution. like the distantly related aspartate or glutamate racemases ...200818258259
persistent bordetella bronchiseptica pneumonia in an immunocompetent infant and genetic comparison of clinical isolates with kennel cough vaccine strains.an infant who experienced recurrent episodes of respiratory failure received a diagnosis of pertussis on the basis of immunofluorescence testing, but culture revealed macrolide-resistant bordetella bronchiseptica. genetic analysis demonstrated that the child was not infected with a kennel cough vaccine strain, although the family's dog had recently been vaccinated. the infection cleared with imipenem therapy.200818260750
subcutaneous vaccination with attenuated salmonella enterica serovar choleraesuis c500 expressing recombinant filamentous hemagglutinin and pertactin antigens protects mice against fatal infections with both s. enterica serovar choleraesuis and bordetella bronchiseptica.salmonella enterica serovar choleraesuis strain c500 is a live, attenuated vaccine that has been used in china for over 40 years to prevent piglet paratyphoid. we compared the protective efficacies of subcutaneous (s.c.) and oral vaccination of balb/c mice with c500 expressing the recombinant filamentous hemagglutinin type i domain and pertactin region 2 domain antigen (rf1p2) of bordetella bronchiseptica. protective efficacy against both s. enterica serovar choleraesuis infection in an oral fat ...200818268026
screening, cloning, expression, and purification of an acidic arylmalonate decarboxylase from enterobacter cloacae ku1313.we have already isolated, purified, and characterized arylmalonate decarboxylases (amdase; ec. 4.1.1.76) from alcaligenes bronchisepticus ku1201 and achromobacter sp. ku1311. these are unique enzymes that give optically pure alpha-arylpropionates from the corresponding alpha-aryl-alpha-methylmalonates. recently, we have further screened novel amdase producers from soil samples under acidic conditions and succeeded in isolating enterobacter cloacae ku1313. the gene encoding the enzyme was cloned ...200818283449
a temperature-regulated campylobacter jejuni gluconate dehydrogenase is involved in respiration-dependent energy conservation and chicken colonization.campylobacter jejuni is a gastrointestinal pathogen of humans but can asymptomatically colonize the avian gut. c. jejuni therefore grows at both 37 degrees c and 42 degrees c, the internal temperatures of humans and birds respectively. microarray and proteomic studies on temperature regulation in c. jejuni strain 81-176 revealed the upregulation at 42 degrees c of two proteins, cj0414 and cj0415, orthologous to gluconate dehydrogenase (gadh) from pectobacterium cypripedii. 81-176 demonstrated ga ...200818284594
alveolar macrophages are indispensable for controlling influenza viruses in lungs of pigs.alveolar macrophages constitutively reside in the respiratory tracts of pigs and humans. an in vivo role of alveolar macrophages in defending against influenza viruses in mice infected with a reassorted influenza virus, 1918 ha/na:tx/91, was reported, but there has been no report on an in vivo role of alveolar macrophages in a natural host such as a pig using currently circulating human influenza virus. here we show that in vivo depletion of alveolar macrophages in pigs by dichloromethylene diph ...200818287245
authors' reply to 'misidentification of bordetella bronchiseptica as bordetella pertussis using a newly described rt-pcr targeting the pertactin gene'. 200818287309
polysaccharides cellulose, poly-beta-1,6-n-acetyl-d-glucosamine, and colanic acid are required for optimal binding of escherichia coli o157:h7 strains to alfalfa sprouts and k-12 strains to plastic but not for binding to epithelial cells.when escherichia coli o157:h7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. in contrast, laboratory k-12 strains of e. coli do not bind to sprouts under similar conditions. the roles of e. coli o157:h7 lipopolysaccharide (lps), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. an lps mutant had no effect on the binding of the pathogenic strain. cellulose synthase mutants showed a significant reduction in bindi ...200818310435
associations between pathogens in healthy pigs and pigs with pneumonia.the aim of this study was to evaluate the associations between different pathogens in the development of pneumonia and bronchopneumonia in pigs. samples of bronchoalveolar lavage fluid from 100 pigs showing no clinical signs and 239 pigs with clinical signs of respiratory disease were examined for mycoplasma hyopneumoniae, mycoplasma hyorhinis, us-type porcine respiratory and reproductive syndrome virus (prrsv), eu-type prrsv, porcine circovirus type 2 (pcv-2), influenza virus type a, alpha-haem ...200818310558
a retrospective study of canine persistent nasal disease: 80 cases (1998-2003).persistent canine nasal disease is a common complaint in small animal practice; however, an etiologic diagnosis can be difficult to establish. the aim of this retrospective study was to determine the percentage of cases for which the etiology was determined in our hospital population. medical records from 80 dogs met the criteria of inclusion in the study. nonspecific rhinitis was identified in 23.7% of cases. other diagnoses were neoplasia (15.0%), fungal infection (nasal aspergillosis) (8.7%), ...200818320982
nonhuman primate infections after organ transplantation.nonhuman primates, primarily rhesus macaques (macaca mulatta), cynomolgus macaques (macaca fascicularis), and baboons (papio spp.), have been used extensively in research models of solid organ transplantation, mainly because the nonhuman primate (nhp) immune system closely resembles that of the human. nonhuman primates are also frequently the model of choice for preclinical testing of new immunosuppressive strategies. but the management of post-transplant nonhuman primates is complex, because it ...200818323582
identification of bordetella spp. in respiratory specimens from individuals with cystic fibrosis.bordetella spp. are not normally included when considering the opportunistic bacterial species that are typically involved in respiratory tract infections in individuals with cystic fibrosis (cf). by using a combination of bacterial genotyping and 16s rdna sequencing, bordetella spp. were identified in cultures obtained from 43 individuals with cf. most (n = 23) patients were infected with bordetella bronchiseptica/parapertussis; five were infected with bordetella hinzii, four with bordetella pe ...200818325036
concentration and emission of airborne contaminants in a laboratory animal facility housing rabbits.characterization of animal housing conditions can determine the frequency of bedding and cage changes, which are not standardized from facility to facility. rabbits produce noticeable odors, and their excreta can scald and stain cages. our facility wanted to document measurable airborne contaminants in a laboratory rabbit room in which excreta pans were changed weekly and cages changed biweekly. contaminants included particulate, endotoxin, ammonia, carbon dioxide, and a rabbit salivary protein ...200818351721
comparison of serological and real-time pcr assays to diagnose bordetella pertussis infection in 2007.bacterial culture for diagnosing pertussis infection has high specificity but poor sensitivity and is slow. highly sensitive real-time pcr assays and single-serum pertussis serology have been developed to overcome these limitations, but there are few data available on the relative sensitivities and specificities of such assays for pertussis diagnosis. using data on 195 participants (>or=7 years old) from an epidemiological study, we assessed the sensitivity, specificity, and performance (youden ...200818367565
the c3 domain of pasteurella multocida toxin is the minimal domain responsible for activation of gq-dependent calcium and mitogenic signaling.the large 1285-amino-acid protein toxin from pasteurella multocida (pmt) is a multifunctional single-chain polypeptide that binds to and enters eukaryotic cells and acts intracellularly to promote g(q) and g(12/13) protein-dependent calcium and mitogenic signal transduction. previous studies indicated that the intracellular activity domain responsible for pmt action was located within the c-terminal 600-700 amino acids. in this study, we have exogenously expressed a series of n- and c-terminal p ...200818369188
isolated weaning technology: humane benefits and concerns in the production of pork.the age at which piglets are separated from the sow has been identified as an animal welfare risk in current swine production systems. animal welfare gains of a minimal disease state must be objectively balanced against the welfare costs of early weaning. veterinary practitioners should continue to participate in the development and validation of humane animal production methods.200818390104
norepinephrine mediates acquisition of transferrin-iron in bordetella bronchiseptica.previous research demonstrated that the sympathoadrenal catecholamine norepinephrine could promote the growth of bordetella bronchiseptica in iron-restricted medium containing serum. in this study, norepinephrine was demonstrated to stimulate growth of this organism in the presence of partially iron-saturated transferrin but not lactoferrin. although norepinephrine is known to induce transcription of the bordetella bfea enterobactin catechol xenosiderophore receptor gene, neither a bfea mutant n ...200818390651
atrophic rhinitis vaccine composition triggers different serological profiles that do not correlate with protection.atrophic rhinitis (ar) is a widespread and economically important disease of swine caused by bordetella bronchiseptica and pasteurella multocida. it can be controlled by vaccination. this study investigates the effect of altering the composition (adjuvants and/or addition of formalin-inactivated p. multocida toxin, fpmt) of conventional vaccines on the serological profile and on protection against ar in swine. a significantly higher b. bronchiseptica specific antibody titre was detected for vacc ...200818401954
insights from the complete genome sequence of mycobacterium marinum on the evolution of mycobacterium tuberculosis.mycobacterium marinum, a ubiquitous pathogen of fish and amphibia, is a near relative of mycobacterium tuberculosis, the etiologic agent of tuberculosis in humans. the genome of the m strain of m. marinum comprises a 6,636,827-bp circular chromosome with 5424 cds, 10 prophages, and a 23-kb mercury-resistance plasmid. prominent features are the very large number of genes (57) encoding polyketide synthases (pkss) and nonribosomal peptide synthases (nrpss) and the most extensive repertoire yet repo ...200818403782
helicobacter hepaticus infection promotes colon tumorigenesis in the balb/c-rag2(-/-) apc(min/+) mouse.adenomatous polyposis coli (apc) mutations are linked to human and mouse colorectal cancers. the apc multiple intestinal neoplasia (min) mouse mutation causes adenomas to develop throughout the small and large intestines. the balb-min (c.b6-apc(min/+)) congenic strain was generated by backcrossing into balb/c the apc(min) allele from c57bl/6j-apc(min/+) mice. balb-min mice have a low tumor multiplicity (27.4 small intestine tumors/mouse) and a relatively long life span (>1 year) that makes them ...200818411292
glucosamine found as a substituent of both phosphate groups in bordetella lipid a backbones: role of a bvgas-activated arnt ortholog.endotoxins are amphipathic lipopolysaccharides (lpss), major constituents of the outer membrane of gram-negative bacteria. they consist of a lipid region, covalently linked to a core oligosaccharide, to which may be linked a repetitive glycosidic chain carrying antigenic determinants. most of the biological activities of endotoxins have been associated with the lipid moiety of the molecule: unique to gram-negative bacteria, lps is a ligand of the mammalian tlr4-md2-cd14 pathogen recognition rece ...200818424515
serendipitous discovery of an immunoglobulin-binding autotransporter in bordetella species.we describe the serendipitous discovery of batb, a classical-type bordetella autotransporter (at) protein with an approximately 180-kda passenger domain that remains noncovalently associated with the outer membrane. like genes encoding all characterized protein virulence factors in bordetella species, batb transcription is positively regulated by the master virulence regulatory system bvgas. batb is predicted to share similarity with immunoglobulin a (iga) proteases, and we showed that batb bind ...200818426869
agr-mediated dispersal of staphylococcus aureus biofilms.the agr quorum-sensing system of staphylococcus aureus modulates the expression of virulence factors in response to autoinducing peptides (aips). recent studies have suggested a role for the agr system in s. aureus biofilm development, as agr mutants exhibit a high propensity to form biofilms, and cells dispersing from a biofilm have been observed displaying an active agr system. here, we report that repression of agr is necessary to form a biofilm and that reactivation of agr in established bio ...200818437240
transmission of avian influenza virus (h3n2) to dogs.in south korea, where avian influenza virus subtypes h3n2, h5n1, h6n1, and h9n2 circulate or have been detected, 3 genetically similar canine influenza virus (h3n2) strains of avian origin (a/canine/korea/01/2007, a/canine/korea/02/2007, and a/canine/korea/03/2007) were isolated from dogs exhibiting severe respiratory disease. to determine whether the novel canine influenza virus of avian origin was transmitted among dogs, we experimentally infected beagles with this influenza virus (h3n2) isola ...200818439355
escherichia coli biofilms.escherichia coli is a predominant species among facultative anaerobic bacteria of the gastrointestinal tract. both its frequent community lifestyle and the availability of a wide array of genetic tools contributed to establish e. coli as a relevant model organism for the study of surface colonization. several key factors, including different extracellular appendages, are implicated in e. coli surface colonization and their expression and activity are finely regulated, both in space and time, to ...200818453280
bordetella bronchiseptica responses to physiological reactive nitrogen and oxygen stresses.bordetella bronchiseptica can establish prolonged airway infection consistent with a highly developed ability to evade mammalian host immune responses. upon initial interaction with the host upper respiratory tract mucosa, b. bronchiseptica are subjected to antimicrobial reactive nitrogen species (rns) and reactive oxygen species (ros), effector molecules of the innate immune system. however, the responses of b. bronchiseptica to redox species at physiologically relevant concentrations (nm-micro ...200818462394
[expression of prn gene of bordetella bronchiseptica and development of a recombinant protein-based indirect elisa for antibodies detection].we developed an indirect elisa method for detecting bordetella bronchiseptica (bb) pertactin antibodies based on the recombinant pertactin protein expressed in escherichia coli (de3) strain.200818479059
[protecting mice from fatal bordetella bronchiseptica infection by immunization with recombinant pertactin antigens].we evaluated the efficacy of the recombinant pertactin (prn)-specific active or passive immunization against bordetella bronchiseptica (bb) in an aerosol challenge model established by using balb/c mice.200818479060
inter- and intraserotypic variation in the streptococcus pyogenes rgg regulon.human isolates of streptococcus pyogenes, a gram-positive bacterium, are characterized by significant genetic and phenotypic variation. the rgg locus, also known as ropb, is a global transcriptional regulator of genes associated with metabolism, stress responses, and virulence in s. pyogenes strain nz131 (serotype m49). to assess the breadth of the rgg regulon, the rgg gene was inactivated in three additional strains representing serotypes m1 (strains sf370 and mgas5005) and m49 (strain cs101). ...200818479433
the porcine lung as a potential model for cystic fibrosis.airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (cf). however, understanding the pathogenesis of cf lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. although the gene encoding the cystic fibrosis transmembrane conductance regulator (cftr) has been targeted in mice, cf mice fail to develop lung or pancreatic disease like that in humans. in many respects, the anatomy, biochemistry, ...200818487356
photorhabdus luminescens genes induced upon insect infection.photorhabdus luminescens is a gram-negative luminescent enterobacterium and a symbiote to soil nematodes belonging to the species heterorhabditis bacteriophora. p.luminescens is simultaneously highly pathogenic to insects. this bacterium exhibits a complex life cycle, including one symbiotic stage characterized by colonization of the upper nematode gut, and a pathogenic stage, characterized by release from the nematode into the hemocoel of insect larvae, resulting in rapid insect death caused by ...200818489737
control of bacterial biofilms with marine alkaloid derivatives.bacterial biofilms are defined as a community of surface-attached bacteria that are protected by an extracellular matrix of biomolecules. we have recently reported the synthesis of a small molecule, denoted tage, based on the natural product bromoageliferin and demonstrated that tage has anti-biofilm activity against pseudomonas aeruginosa. herein we demonstrate that tage: (1) does not have selective toxicity against cells within the biofilm state, (2) will inhibit biofilm development under flow ...200818493660
the major facilitator superfamily-type transporter ymfe and the multidrug-efflux activator mta mediate bacillibactin secretion in bacillus subtilis.high-affinity iron acquisition in bacillus subtilis is mediated via the bacillibactin catechole siderophore pathway. three of the four essential pathway steps, bacillibactin synthesis, fe-bacillibactin uptake, and fe-bacillibactin hydrolysis have been characterized previously. the functional and regulatory components for bacillibactin secretion, the second step of the siderophore pathway, remained unknown. in this study, the screening of a b. subtilis exporter mutant library led to the identific ...200818502870
prevalence of actinobacillus pleuropneumoniae, actinobacillus suis, haemophilus parasuis, pasteurella multocida, and streptococcus suis in representative ontario swine herds.tonsillar and nasal swabs were collected from weanling pigs in 50 representative ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. all but 1 herd (2%) tested positive for streptococcus suis by polymerase chain reaction (pcr); 48% of herds were s. suis serovar 2, 1/2 positive. in all but 2 herds there was evidence of haemophilus parasuis infection. in contrast, toxigenic strains of pasteurella multocida were detected by a p. multocida--enz ...200818505187
selective ligand recognition by a diversity-generating retroelement variable protein.diversity-generating retroelements (dgrs) recognize novel ligands through massive protein sequence variation, a property shared uniquely with the adaptive immune response. little is known about how recognition is achieved by dgr variable proteins. here, we present the structure of the bordetella bacteriophage dgr variable protein major tropism determinant (mtd) bound to the receptor pertactin, revealing remarkable adaptability in the static binding sites of mtd. despite large dissimilarities in ...200818532877
prevalence of selected infectious organisms and comparison of two anatomic sampling sites in shelter cats with upper respiratory tract disease.in order to describe the isolation rates of potential pathogens and to compare anatomic sampling site suitability, nasal and pharyngeal swabs were taken from cats with acute clinical upper respiratory disease in a humane society. dna of feline herpesvirus-1 was amplified from 51 of 52 cats sampled, mycoplasma species were cultured or detected by pcr in samples from 34 of 42 cats sampled for both culture and pcr, and bordetella bronchiseptica was isolated from three of 59 cats sampled for aerobic ...200818539065
saccharide/protein conjugate vaccines for bordetella species: preparation of saccharide, development of new conjugation procedures, and physico-chemical and immunological characterization of the conjugates.bordetellae are gram-negative bacilli causing respiratory tract infections of mammals and birds. clinically important are b. pertussis, b. parapertussis and b. bronchiseptica. b. pertussis vaccines have been successful in preventing pertussis in infants and children. veterinary vaccines against b. bronchiseptica are available, but their efficacy and mode of action are not established. there is no vaccine against b. parapertussis. based on the concept that immunity to non-capsulated gram-negative ...200818539367
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1401 - 1500 of 2471