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comparative studies on the ultrastructure of l forms obtained from s and r variants of brucella suis 1330.electron-microscopic studies were carried out on s and r variants of brucella suis 1330 and the production of l forms induced with the use of penicillin. no variations were established in the ultrastructure of the initial forms. however, essential differences were observed in the ultrastructure between the latter and the l-transformed brucellae as well as changes that differentiated the ultrastructure of l forms obtained from s variants from that of l forms obtained from r variants. in both case ...1978636707
[development of spleenic infection in the mouse following intravenous inoculation of various species of brucella in smooth (s) or rough (r) phases].the bacterial population in the spleen of mice inoculated intravenously by brucella abortus 544 (s), brucella suis 1330 (s), brucella melitensis 115 (r) or brucella canis rm 666(r) is studied kinetically. like the s strains of brucella, the r strains are able to multiply in the mouse spleen. the consequences for the tests of vaccines against natural infections produced by s or r strains of brucella are discussed.1975810263
[two anti-brucella sf311 and s480 monoclonal antibodies with protective activity against brucella pathogenic for mice].two "protective" monoclonal anti-brucella antibodies are described (sf311-igg2a and s480-iga) both of them accelerate the blood clearance of i.v. inoculated brucella suis 1330 and decrease murine splenic infection on day 7.19852938694
genetic factors involved in murine resistance to experimental brucellosis.c57 b1/6 are more resistant than dba2 mice to iv inoculation of brucella suis 1330. this difference does not concern the blood clearance of the injected bacteria or the number of infective colonies in the spleen at very early (less than 24 h) or at late (greater than 2 months) stages but the splenic infection at intermediate stages with maximal differences between days 7 and 14. the "resistance" character is inherited by f1 and backcrosses as a partially dominant character with polygenic control ...19846593265
genetic factors involved in murine susceptibility to experimental brucellosis.c57bl/6 are more resistant than dba2 mice to brucella suis 1330. this difference does not concern the blood clearance of the i.v. inoculated bacteria or the number of infective colonies in the spleen at very early stages but the splenic infection at later stages with maximal differences on day +7. the "resistance" character is inherited by f1 and back-crosses as a partially dominant character with polygenic control and a better expression of resistant factor(s) in females. this phenomenon of sex ...19816957160
nucleotide sequence and expression of the gene encoding the major 25-kilodalton outer membrane protein of brucella ovis: evidence for antigenic shift, compared with other brucella species, due to a deletion in the gene.the nucleotide sequences encoding the major 25-kda outer membrane protein (omp) (omp25 genes) of brucella ovis 63/290, brucella melitensis 16m, brucella suis 1330, brucella canis rm6/66, and brucella neotomae 5k33 (all reference strains) were determined and compared with that of brucella abortus 544 (p. de wergifosse, p. lintermans, j. n. limet, and a. cloeckaert, j. bacteriol. 177:1911-1914, 1995). the major difference found was between the omp25 gene of b. ovis and those of the other brucella ...19968675306
response of brucella suis 1330 and b. canis rm6/66 to growth at acid ph and induction of an adaptive acid tolerance response.acid ph is an environmental stress often encountered by brucella during both the "environmental" and the "pathogenic" stages of its life. we have investigated the behaviour of b. suis biovar 1 and b. canis in acid conditions. growth at suboptimal ph was characterized by a dramatic reduction in growth yield due to an early onset of stationary phase. b. suis was more resistant to low ph than b. canis, which lysed at ph 4.6. viable counts measured after a 4-h acid shock at ph 3.2 showed that the re ...19979765795
a homologue of the agrobacterium tumefaciens virb and bordetella pertussis ptl type iv secretion systems is essential for intracellular survival of brucella suis.analysis of a tnblam mutant of brucella suis 1330, identified as being unable to multiply in hela cells, allowed us to identify a 11 860 bp region of the b. suis genome encoding a type iv secretion system, homologous to the virb system of agrobacterium tumefaciens and the ptl system of bordetella pertussis. dna sequence revealed 12 open reading frames (orfs) encoding homologues of the 11 virb proteins present in the pti plasmid of agrobacterium with a similar genetic organization, and a twelfth ...199910510235
identification of brucella suis genes affecting intracellular survival in an in vitro human macrophage infection model by signature-tagged transposon mutagenesis.bacteria of the genus brucella are facultative intracellular pathogens which have developed the capacity to survive and multiply in professional and nonprofessional phagocytes. the genetic basis of this aspect of brucella virulence is still poorly understood. to identify new virulence factors, we have adapted signature-tagged transposon mutagenesis, which has been used essentially in animal models, to an in vitro human macrophage infection model. a library of 1,152 brucella suis 1330 tagged mini ...200010678941
identification of the nik gene cluster of brucella suis: regulation and contribution to urease activity.analysis of a brucella suis 1330 gene fused to a gfp reporter, and identified as being induced in j774 murine macrophage-like cells, allowed the isolation of a gene homologous to nika, the first gene of the escherichia coli operon encoding the specific transport system for nickel. dna sequence analysis of the corresponding b. suis nik locus showed that it was highly similar to that of e. coli except for localization of the nikr regulatory gene, which lies upstream from the structural nikabcde ge ...200111133934
secretion of listeriolysin by brucella suis inhibits its intramacrophagic replication.the introduction into brucella suis 1330 of a plasmid allowing the heterologous expression of a hybrid cytolysin containing listeriolysin from listeria monocytogenes, and its export via the escherichia coli hemolysin secretion pathway, resulted in secretion of active listeriolysin monitored by erythrocyte lysis. in contrast to observations with the nonhemolytic control strain, the phagosomes of infected human monocytes containing the hemolytic b. suis were partially disrupted, and this strain fa ...200111254648
major outer membrane protein omp25 of brucella suis is involved in inhibition of tumor necrosis factor alpha production during infection of human macrophages.brucella spp. can establish themselves and cause disease in humans and animals. the mechanisms by which brucella spp. evade the antibacterial defenses of their host, however, remain largely unknown. we have previously reported that live brucellae failed to induce tumor necrosis factor alpha (tnf-alpha) production upon human macrophage infection. this inhibition is associated with a nonidentified protein that is released into culture medium. outer membrane proteins (omps) of gram-negative bacteri ...200111447156
identification of a quorum-sensing signal molecule in the facultative intracellular pathogen brucella melitensis.brucella melitensis is a gram-negative alpha2-proteobacterium responsible for abortion in goats and for malta fever in humans. this facultative intracellular pathogen invades and survives within both professional and nonprofessional phagocytes. a dichloromethane extract of spent culture supernatant from b. melitensis induces bioluminescence in an escherichia coli acyl-homoserine lactone (acyl-hsl) biosensor strain based upon the activity of the lasr protein of pseudomonas aeruginosa. hplc fracti ...200212010991
purification and characterization of an immunogenic aminopeptidase of brucella melitensis.an immunogenic aminopeptidase was purified from brucella melitensis strain vtrm1. the purification procedure consisted of ammonium sulfate fractionation and three chromatographic steps. this procedure resulted in a yield of 29% and a 144-fold increase in specific activity. the aminopeptidase appeared to be a monomeric enzyme with a molecular mass of 96 kda and an isoelectric point of 4.8. its activity was optimal at ph 7.0 at 40 degrees c. the enzyme was strongly inhibited by edta, 1,10-phenathr ...200312933870
molecular characterization of brucella abortus chromosome ii recombination.large-scale genomic rearrangements including inversions, deletions, and duplications are significant in bacterial evolution. the recently completed brucella melitensis 16m and brucella suis 1330 genomes have facilitated the investigation of such events in the brucella spp. suppressive subtractive hybridization (ssh) was employed in identifying genomic differences between b. melitensis 16m and brucella abortus 2308. analysis of 45 ssh clones revealed several deletions on chromosomes of b. abortus ...200314526025
dna polymorphism in the omp25/omp31 family of brucella spp.: identification of a 1.7-kb inversion in brucella cetaceae and of a 15.1-kb genomic island, absent from brucella ovis, related to the synthesis of smooth lipopolysaccharide.five genes homologous to the well-known omp25 and omp31 genes, that code for two major brucella spp. outer membrane proteins (omps), have been detected in the genome of brucella melitensis 16m and brucella suis 1330. in this work we have determined the nucleotide sequence of these five genes, named omp31b, omp25b, omp25c, omp25d and omp22, in the six classical brucella species reference strains and in representative strains of the recently proposed species brucella cetaceae and brucella pinniped ...200415374004
secondary structure in the target as a confounding factor in synthetic oligomer microarray design.secondary structure in the target is a property not usually considered in software applications for design of optimal custom oligonucleotide probes. it is frequently assumed that eliminating self-complementarity, or screening for secondary structure in the probe, is sufficient to avoid interference with hybridization by stable secondary structures in the probe binding site. prediction and thermodynamic analysis of secondary structure formation in a genome-wide set of transcripts from brucella su ...200515755320
completion of the genome sequence of brucella abortus and comparison to the highly similar genomes of brucella melitensis and brucella suis.brucellosis is a worldwide disease of humans and livestock that is caused by a number of very closely related classical brucella species in the alpha-2 subdivision of the proteobacteria. we report the complete genome sequence of brucella abortus field isolate 9-941 and compare it to those of brucella suis 1330 and brucella melitensis 16 m. the genomes of these brucella species are strikingly similar, with nearly identical genetic content and gene organization. however, a number of insertion-dele ...200515805518
carboxyl-terminal protease regulates brucella suis morphology in culture and persistence in macrophages and mice.the putative carboxyl-terminal processing protease (ctpa) of brucella suis 1330 is a member of a novel family of endoproteases involved in the maturation of proteins destined for the cell envelope. the b. suis ctpa protein shared up to 77% homology with ctpa proteins of other bacteria. a ctpa-deficient brucella strain (1330deltactpa), generated by allelic exchange, produced smaller colonies on enriched agar plates and exhibited a 50% decrease in growth rate in enriched liquid medium and no growt ...200516077124
the incp island in the genome of brucella suis 1330 was acquired by site-specific integration.an 18,228-bp region containing open reading frames predicted to be derived from the incp plasmid or phage ancestors is present in the genomes of brucella suis biovars 1 to 4, b. canis, b. neotomae, and strains isolated from marine mammals, but not in b. melitensis, b. abortus, b. ovis, and b. suis biovar 5. the presence of circular excision intermediates and the results of an analysis of sequenced bacterial genomes suggest that the region downstream of the guaa gene is a hotspot for site-specifi ...200516239585
insight in to the phylogeny of polyhydroxyalkanoate biosynthesis: horizontal gene transfer.polyhydroxyalkanoates (phas) are gaining more and more importance the world over due to their structural diversity and close analogy to plastics. their biodegradability makes them extremely desirable substitutes for synthetic plastics. phas are produced in organisms under certain stress conditions. here, we investigated 253 sequenced (completely and unfinished) genomes for the diversity and phylogenetics of the pha biosynthesis. discrepancies in the phylogenetic trees for phaa, phab and phac gen ...200717113245
identification of vcea and vcec, two members of the vjbr regulon that are translocated into macrophages by the brucella type iv secretion system.survival and replication inside host cells by brucella spp. requires a type iv secretion system (t4ss), encoded by the virb locus. however, the identity of the molecules secreted by the t4ss has remained elusive. we hypothesized that proteins translocated by the t4ss would be co-regulated with the virb operon. the luxr family regulator vjbr, known to regulate virb, bound a fragment of the virb promoter containing an 18 bp palindromic motif (virb promoter box), showing that vjbr regulated the vir ...200819019140
smooth brucella strains invade and replicate in human lung epithelial cells without inducing cell death.inhalation is a common route for brucella infection. we investigated whether brucella species can invade and replicate within alveolar(a549) and bronchial (calu-6 and 16hbe14o-) human epithelial cells. the number of adherent and intracellular bacteria was higher for rough strains (brucella canis and brucella abortus rb51) than for smooth strains (b. abortus 2308 and brucella suis 1330). only smooth strains exhibited efficient intracellular replication (1.5-3.5 log increase at 24 h p.i.). a b. ab ...200919397873
brucella microti: the genome sequence of an emerging pathogen.using a combination of pyrosequencing and conventional sanger sequencing, the complete genome sequence of the recently described novel brucella species, brucella microti, was determined. b. microti is a member of the genus brucella within the alphaproteobacteria, which consists of medically important highly pathogenic facultative intracellular bacteria. in contrast to all other brucella species, b. microti is a fast growing and biochemically very active microorganism with a phenotype more simila ...200919653890
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
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
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