| evaluation of an indirect elisa for the diagnosis of bovine brucellosis in milk and serum samples in dairy cattle in argentina. | an indirect enzyme-linked immunosorbent assay (elisa) for brucella abortus antibodies detection in bovine milk and serum samples was validated. the assay use b. abortus smooth lipopolysaccharide as antigen, immobilized on a polystyrene matrix; milk diluted 1:2 or serum diluted 1:50, in a buffer containing divalent cation chelating agents edta and egta (ethyleneglycol-bis-aminoether-n,n,n',n'-tetraacetic acid) to reduce non-specific reactions; and a mouse monoclonal antibody specific for an epito ... | 1998 | 9785376 |
| estimation of the biological activity (potency) of batches of brucellin prepared from a mucoid strain of brucella abortus. | a study was conducted to determine the repeatability of a procedure used to prepare brucellin from a mucoid strain of brucella abortus, and to determine the biological activity of those brucellins. the brucellins were standardized to contain 1 mg protein/ml, and their potency was estimated according to the european pharmacopoeia norm for tuberculin. estimation of the potency was done in cattle that have been sensitized with living or killed brucellae. a brucellin that effectively detected acute ... | 1998 | 9791877 |
| evaluation of lipopolysaccharides and polysaccharides of different epitopic structures in the indirect enzyme-linked immunosorbent assay for diagnosis of brucellosis in small ruminants and cattle. | brucella abortus and brucella melitensis have surface lipopolysaccharides and polysaccharides carrying b. melitensis-type (m) and b. abortus-type (a) epitopes as well as common (c) epitopes present in all smooth brucella biotypes. crude lipopolysaccharides, hydrolytic o polysaccharides, and native hapten polysaccharides of mc or ac specificity were evaluated in indirect enzyme-linked immunosorbent assays with polyclonal, monoclonal, or protein g conjugates by using sera from cattle, sheep, and g ... | 1998 | 9801329 |
| extracellular and cytosolic iron superoxide dismutase from mycobacterium bovis bcg. | two forms of iron superoxide dismutase (sod) were purified from cell extract (ce) and culture filtrate (cf) of mycobacterium bovis bcg, respectively. the molecular weight of both enzymes was estimated to be approximately 84,000 by gel filtration, whereas that of their subunits was 21,500, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that each of purified enzymes is composed of four identical subunits. the specific activities of ce sod and cf sod were 3,8 ... | 1998 | 9801335 |
| o-polysaccharide epitopic heterogeneity at the surface of brucella spp. studied by enzyme-linked immunosorbent assay and flow cytometry. | smooth brucella strains are classified into three serotypes, i.e., a+m-, a-m+, and a+m+, according to slide agglutination with a and m monospecific polyclonal sera. the epitopes involved have been located on the o-polysaccharide (o-ps) moiety of the smooth lipopolysaccharide (s-lps), which represents the most exposed antigenic structure on the surface of brucella spp. by use of monoclonal antibodies (mabs) a number of epitope specificities on the o-ps have been reported: a, m, and epitopes share ... | 1998 | 9801349 |
| safety of brucella abortus strain rb51 in bison. | to determine the safety of brucella abortus strain rb51 (srb51) vaccine in american bison (bison bison), 31 animals from a herd with brucellosis were used. in october 1996, 10 adult bison males and seven calves were vaccinated with the standard calfhood cattle dose of 1.8 x 10(10) colony forming units (cfu) of srb51 subcutaneously while the adult females received the standard adult cattle dose of 1 x 10(9) cfu. western immunoblot indicated the presence of srb51 antibodies following vaccination. ... | 1998 | 9813857 |
| cloning and sequencing of yajc and secd homologs of brucella abortus and demonstration of immune responses to yajc in mice vaccinated with b. abortus rb51. | to identify brucella antigens that are potentially involved in stimulating a protective cell-mediated immune response, a gene library of brucella abortus 2308 was screened for the expression of antigens reacting with immunoglobulin g2a antibodies from balb/c mice vaccinated with b. abortus rb51. one selected positive clone (clone mcb68) contained an insert of 2.6 kb; nucleotide sequence analysis of this insert revealed two open reading frames (orfs). the deduced amino acid sequences of the first ... | 1998 | 9826342 |
| brucella abortus transits through the autophagic pathway and replicates in the endoplasmic reticulum of nonprofessional phagocytes. | brucella abortus is an intracellular pathogen that replicates within a membrane-bounded compartment. in this study, we have examined the intracellular pathway of the virulent b. abortus strain 2308 (s2308) and the attenuated strain 19 (s19) in hela cells. at 10 min after inoculation, both bacterial strains are transiently detected in phagosomes characterized by the presence of early endosomal markers such as the early endosomal antigen 1. at approximately 1 h postinoculation, bacteria are locate ... | 1998 | 9826346 |
| invasion of human oral epithelial cells by prevotella intermedia. | invasion of oral epithelial cells by pathogenic oral bacteria may represent an important virulence factor in the progression of periodontal disease. here we report that a clinical isolate of prevotella intermedia, strain 17, was found to invade a human oral epithelial cell line (kb), whereas p. intermedia 27, another clinical isolate, and p. intermedia 25611, the type strain, were not found to invade the cell line. invasion was quantified by the recovery of viable bacteria following a standard a ... | 1998 | 9826397 |
| effects of bacterial antibiotic production on rhizosphere microbial communities from a culture-independent perspective | the effects of antibiotic production on rhizosphere microbial communities of field-grown phaseolus vulgaris were assessed by using ribosomal intergenic spacer analysis. inoculum strains of rhizobium etli ce3 differing only in trifolitoxin production were used. trifolitoxin production dramatically reduced the diversity of trifolitoxin-sensitive members of the alpha subdivision of the class proteobacteria with little apparent effect on most microbes. | 1998 | 9835600 |
| standardization of smooth lipopolysaccharide preparations for use in diagnostic serological tests for bovine antibody brucella abortus. | a procedure for standardizing brucella abortus smooth lipopolysaccharide used in diagnostic tests for brucellosis is proposed. the procedure is based on the reactivity of antigen preparations with a panel of sera with or without antibody to b. abortus using a set of parameters established with 13 antigen preparations. for each serum dilution, a mean and two standard deviations were calculated in the indirect and competitive enzyme immunoassays. if data obtained with an antigen preparation, using ... | 1998 | 9840296 |
| crystallization and preliminary x-ray diffraction analysis of the lumazine synthase from brucella abortus. | lumazine synthase from brucella abortus was overexpressed in escherichia coli, refolded, and purified to apparent homogeneity. crystals of lumazine synthase were grown by the hanging drop vapor diffusion method using polyethylene glycol 8000 or ammonium sulfate as precipitants. they belong to the trigonal space group p321 with cell parameters a = b = 132.00a, c = 167.25 a. a complete diffraction data set to 3.7 a resolution has been collected using synchrotron radiation. preliminary analysis of ... | 1998 | 9843672 |
| protection against infection and abortion induced by virulent challenge exposure after oral vaccination of cattle with brucella abortus strain rb51. | to determine efficacy of orally administered brucella abortus vaccine strain rb51 against virulent b abortus challenge exposure in cattle as a model for vaccination of wild ungulates. | 1998 | 9858409 |
| origin of a chloroplast protein importer. | during evolution, chloroplasts have relinquished the majority of their genes to the nucleus. the products of transferred genes are imported into the organelle with the help of an import machinery that is distributed across the inner and outer plastid membranes. the evolutionary origin of this machinery is puzzling because, in the putative predecessors, the cyanobacteria, the outer two membranes, the plasma membrane, and the lipopolysaccharide layer lack a functionally similar protein import syst ... | 1998 | 9861056 |
| verification of immunosuppression in chicks caused by cryptosporidium baileyi infection using brucella abortus strain 1119-3. | humoral immune response of young chicks to brucella abortus strain 1119-3 inoculation was monitored to verify the degree of immunosuppression caused by infection with cryptosporidium baileyi. young chicks (2-day-old) were orally inoculated each with 2 x 10(6) oocysts of c. baileyi, and then injected intramuscularly with 0.3 ml b. abortus strain 1119-3 containing 1 x 10(9) living organisms on day 14 postinoculation (pi). serum samples were tested by plate agglutination test on day 17 pi onwards a ... | 1998 | 9868895 |
| diagnosis of bovine brucellosis using a homogeneous fluorescence polarization assay. | to evaluate the fluorescence polarization assay (fpa) for the serological diagnosis of bovine brucellosis, 118 sera from cattle which were culture positive for brucella abortus, 1751 sera from cattle from premises containing cattle infected with b. abortus, 1222 sera from cattle vaccinated with b. abortus strain 19 and 1199 sera from cattle with no evidence of brucellosis were tested in argentina, chile, mexico and in the american states of iowa, missouri and texas. initial determination of sero ... | 1998 | 9880108 |
| is brucella abortus a facultative intracellular pathogen with mitochondria-like activity? | brucella abortus is the agent of bovine brucellosis, a zoonotic disease of worldwide importance. in latently infected humans and animals, acute disease may recur under conditions that decrease the host resistance. this bacterium is considered to be a facultative intracellular pathogen. however, its pathogenic attributes appear reduced in comparison with other gram-negative pathogens. it has been recognized that b. abortus and other brucella species reach their intracellular location inside the r ... | 1998 | 9881835 |
| use of genomics to identify bacterial undecaprenyl pyrophosphate synthetase: cloning, expression, and characterization of the essential upps gene. | the prenyltransferase undecaprenyl pyrophosphate synthetase (di-trans,poly-cis-decaprenylcistransferase; ec 2.5.1.31) was purified from the soluble fraction of escherichia coli by tsk-deae, ceramic hydroxyapatite, tsk-ether, superdex 200, and heparin-actigel chromatography. the protein was labeled with the photolabile analogue of the farnesyl pyrophosphate analogue (e, e)-[1-3h]-(2-diazo-3-trifluoropropionyloxy)geranyl diphosphate and was detected on a sodium dodecyl sulfate-polyacrylamide gel a ... | 1999 | 9882662 |
| the evolutionary origin of the protein-translocating channel of chloroplastic envelope membranes: identification of a cyanobacterial homolog. | the known envelope membrane proteins of the chloroplastic protein import apparatus lack sequence similarity to proteins of other eukaryotic or prokaryotic protein transport systems. however, we detected a putative homolog of the gene encoding toc75, the protein-translocating channel from the outer envelope membrane of pea chloroplasts, in the genome of the cyanobacterium synechocystis sp. pcc 6803. we investigated whether the low sequence identity of 21% reflects a structural and functional rela ... | 1999 | 9892711 |
| monocytes that have ingested yersinia enterocolitica serotype o:3 acquire enhanced capacity to bind to nonstimulated vascular endothelial cells via p-selectin. | reactive arthritis is usually a self-limiting polyarthritis which develops after certain gastrointestinal or urogenital infections. microbial antigens found in the inflamed joints are thought to play a key role in the development of this disease. it is not known how antigens of the pathogenic organisms migrate from the mucosal tissues into the joints. the data presented here show that mononuclear phagocytes which mediate the dissemination of several intracellular pathogens acquire an enhanced ca ... | 1999 | 9916083 |
| in vivo blockage of nitric oxide with aminoguanidine inhibits immunosuppression induced by an attenuated strain of salmonella typhimurium, potentiates salmonella infection, and inhibits macrophage and polymorphonuclear leukocyte influx into the spleen. | our laboratory has previously shown that after immunization with a strain of salmonella typhimurium, sl3235, made avirulent by a blockage in the pathway of aromatic synthesis, murine splenocytes were profoundly suppressed in their capacity to mount an in vitro antibody plaque-forming cell (pfc) response to sheep erythrocytes. evidence indicated that suppression was mediated by nitric oxide (no), since the in vitro addition of ng-monomethyl-l-arginine blocked suppression. the present studies exam ... | 1999 | 9916105 |
| vaccination with live escherichia coli expressing brucella abortus cu/zn superoxide dismutase protects mice against virulent b. abortus. | vaccination of mice with escherichia coli expressing brucella cu/zn superoxide dismutase (sod) [e. coli(pbssod)] induced a significant level of protection against virulent brucella abortus challenge, although this level was not as high as the one reached with b. abortus vaccine strain rb51. in addition, vaccination with e. coli(pbssod) induced antibodies to cu/zn sod and a strong proliferative response of splenocytes when stimulated in vitro with a thioredoxin-cu/zn sod fusion protein. | 1999 | 9916121 |
| osteoarticular complications of brucellosis in an atlantic area of spain. | to assess the frequency and clinical manifestations of osteoarticular brucellosis in an atlantic area of spain. | 1999 | 9918255 |
| [splenic abscess caused by brucella abortus]. | a 23 year-old man with prolonged fever caused by brucella abortus is reported. the uncommon feature of this case was the presence of a spleen abscess identified by computer tomography of the abdomen. patient evolution was favorable after treatment with antibiotics, with complete regression of the lesions. | 1999 | 9927826 |
| the efficacy of the skin delayed-type hypersensitivity using a brucellin prepared from a mucoid strain of brucella abortus to detect brucellosis. | eight-hundred-and-ninety-six cattle belonging to herds officially designated brucella-free, and 190 cattle belonging to infected herds were tested with the skin delayed-type hypersensitivity (sdth) test, using brucellin (273) prepared from a mucoid strain of brucella abortus. an increase in skinfold thickness > or = 2 mm was considered a positive sdth test. the serum agglutination test, complement fixation test and bacteriological examination were used to confirm sdth test results. results show ... | 1999 | 10030130 |
| performance of competitive and indirect enzyme-linked immunosorbent assays, gel immunoprecipitation with native hapten polysaccharide, and standard serological tests in diagnosis of sheep brucellosis. | competitive and standard enzyme-linked immunosorbent assays (elisas), rose bengal (rb), complement fixation, and agar gel immunoprecipitation with native hapten (agid-nh) were compared by using sera from brucella-free, brucella melitensis-infected, and b. melitensis rev1-vaccinated sheep. the most sensitive tests were indirect elisa and rb, and the most specific tests were agid-nh and competitive elisa. we show that rb followed by agid-nh is a simple and effective system for diagnosing sheep bru ... | 1999 | 10066666 |
| serosurvey for antibodies against brucella abortus and leptospira interrogans in pampas deer from brazil. | a survey for antibodies against brucella abortus, and leptospira interrogans was conducted on 17 pampas deer (ozotocerus bezoarticus) from pantanal matogrossense (state of mato grosso do sul, brazil) and on 24 pampas deer from parque nacional de emas (state of goiás, brazil). antibodies against b. abortus were detected by plate agglutination, rose bengal, and complement fixation tests; antibodies against leptospira interrogans were detected by the microscopic agglutination test. all sera were ne ... | 1999 | 10073359 |
| bartonella koehlerae sp. nov., isolated from cats. | two of the 25 bartonella isolates recovered during a prevalence study of bartonella henselae bacteremia in domestic cats from the greater san francisco bay region were found to differ phenotypically and genotypically from all prior b. henselae isolates. these isolates, c-29 and c-30, which were recovered from the blood of two pet cats belonging to the same household, grew on chocolate agar as pinpoint colonies following 14 days of incubation at 35 degrees c in a candle jar but failed to grow on ... | 1999 | 10074535 |
| the alternative sigma factor, sigmae, is critically important for the virulence of salmonella typhimurium. | in escherichia coli, extracytoplasmic stress is partially controlled by the alternative sigma factor, rpoe (sigmae). in response to environmental stress or alteration in the protein content of the cell envelope, sigmae upregulates the expression of a number of genes, including htra. it has been shown that htra is required for intramacrophage survival and virulence in salmonella typhimurium. to investigate whether sigmae-regulated genes other than htra are involved in salmonella virulence, we ina ... | 1999 | 10084987 |
| lipopolysaccharides (lps) of oral black-pigmented bacteria induce tumor necrosis factor production by lps-refractory c3h/hej macrophages in a way different from that of salmonella lps. | some lipopolysaccharide (lps) preparations from s- or r-form members of the family enterobacteriaceae and oral black-pigmented bacteria (porphyromonas gingivalis and prevotella intermedia) are known to activate lps-refractory c3h/hej macrophages. when contaminating proteins are removed from r-form lps of enterobacteriaceae by repurification, however, this ability is lost. in the present study, we investigated the capacity of lps from p. gingivalis, p. intermedia, salmonella minnesota, and salmon ... | 1999 | 10085012 |
| the clinical spectrum of severe septic bursitis in northwestern spain: a 10 year study. | to assess the clinical and microbiological characteristics of septic bursitis in those cases that required treatment at the hospital during the past 10 years in a northwestern area of spain. | 1999 | 10090179 |
| modulation of endocytosis in nuclear factor il-6(-/-) macrophages is responsible for a high susceptibility to intracellular bacterial infection. | activated macrophages kill bacteria, a function known to depend on the expression of nf-il-6. here, it is demonstrated that the attenuated brucella abortus vaccine strain 19 replicates much better in nf-il-6-/- than in nf-il-6(+/+) and nf-il-6(+/+)-activated murine macrophages and at levels comparable to those observed in normal macrophages infected with the pathogenic strain 2308. the role of nf-il-6 in the inhibition of intracellular bacterial replication is related to its control of endocytos ... | 1999 | 10092809 |
| the elisa for the examination of hare sera for anti-brucella antibodies. | hare brucellosis is caused primarily by brucella suis biovar 2. hares along with wild boars are the natural reservoir of this microorganism. in view of restriction of applicability of traditional serological methods the work aimed to develop the elisa to examine hare sera for the presence of anti-brucella antibodies. lipopolysaccharide (lps) antigen obtained from the strain s19 of brucella abortus and the conjugate of antibodies against rabbit immunoglobulin with horseradish peroxidase were used ... | 1999 | 10099027 |
| development and characterization of a fluorescent-bacteriophage assay for detection of escherichia coli o157:h7. | in this paper we describe evaluation and characterization of a novel assay that combines immunomagnetic separation and a fluorescently stained bacteriophage for detection of escherichia coli o157:h7 in broth. when it was combined with flow cytometry, the fluorescent-bacteriophage assay (fba) was capable of detecting 10(4) cells/ml. a modified direct epifluorescent-filter technique (deft) was employed in an attempt to estimate bacterial concentrations. using regression analysis, we calculated tha ... | 1999 | 10103228 |
| responses of cattle to two dosages of brucella abortus strain rb51: serology, clearance and efficacy. | a new brucellosis vaccine, brucella abortus strain rb51 (srb51), is currently recommended for use as a calfhood vaccine in the us at dosages between 1 x 10(10)and 3.4 x 10(10)colony-forming units (cfu). the purpose of the study reported here was to compare responses to minimal and maximal recommended srb51 dosages. eighteen heifer calves were vaccinated subcutaneously with 1.6 x 10(10)cfu of srb51, 3.2 x 10(10)cfu of srb51, or saline (n = 6 per treatment). the vaccine strain was recovered from t ... | 1999 | 10208887 |
| effect of early antibiotic treatment on the antibody response to cytoplasmic proteins of brucella melitensis in mice. | to test whether antibiotic therapy hampers the antibody response to brucella antigens, 30 balb/c mice were infected with brucella melitensis h38 and randomized for treatment with doxycycline administered intraperitoneally for 42 days starting at 7 or 28 days postinfection (p.i.) (groups dox7 and dox28, respectively) or for no treatment (control group). antibodies to smooth lipopolysaccharide (lps) reached peak levels (mean optical density [od] = 2.618) between days 56 and 70 p.i. in the control ... | 1999 | 10225853 |
| role of polymorphonuclear neutrophils in a murine model of chlamydia psittaci-induced abortion. | to assess the role of polymorphonuclear neutrophils (pmns) in chlamydia psittaci infection in a pregnant mouse model, pregnant and nonpregnant swiss of1 mice were depleted of pmns by treatment with the rb6-8c5 monoclonal antibody before intraperitoneal infection with c. psittaci serotype 1. nondepleted mice served as infection controls. depleted mice aborted earlier and had a much higher mortality rate than nondepleted mice. bacteriological analysis showed that the number of chlamydiae isolated ... | 1999 | 10225862 |
| survival of enterococcus faecalis in mouse peritoneal macrophages. | enterococcus faecalis was tested for the ability to persist in mouse peritoneal macrophages in two separate studies. in the first study, the intracellular survival of serum-passaged e. faecalis 418 and two isogenic mutants [cytolytic strain fa2-2(pam714) and non-cytolytic strain fa2-2(pam771)] was compared with that of escherichia coli dh5alpha by infecting balb/c mice intraperitoneally and then monitoring the survival of the bacteria within lavaged peritoneal macrophages over a 72-h period. all ... | 1999 | 10225869 |
| the siderophore 2,3-dihydroxybenzoic acid is not required for virulence of brucella abortus in balb/c mice. | 2,3-dihydroxybenzoic acid (dhba) is the only siderophore described for brucella, and previous studies suggested that dhba might contribute to the capacity of these organisms to persist in host macrophages. employing an isogenic siderophore mutant (deltaentc) constructed from virulent brucella abortus 2308, however, we found that production of dhba is not required for replication in cultured murine macrophages or for the establishment and maintenance of chronic infection in the balb/c mouse model ... | 1999 | 10225929 |
| deficiency in tumor necrosis factor alpha activity does not impair early protective th1 responses against blood-stage malaria. | blood-stage plasmodium chabaudi as infection was controlled by 4 weeks in mice with deletion of tumor necrosis factor p55 and p75 receptors (tnfr-knockout [ko]) and control wild-type (wt) mice, although female tnfr-ko mice showed slightly but significantly higher parasitemia immediately following the peak. serum interleukin 12 (il-12) p70 and gamma interferon (ifn-gamma) levels were similar but tumor necrosis factor alpha levels were significantly higher in tnfr-ko mice than in wt controls. sple ... | 1999 | 10225939 |
| [use of protein-polysaccharide brucella antigen labeled with colloidal gold for detection of specific antibodies by the dot-immunoassay method]. | antibrucella antibodies were detected by dot-immunoassay with colloid gold label of antigen. the specific antigen was protein-polysaccharide complex (ppc) isolated from vaccine strain brucella abortus 19 ba by acetic acid hydrolysis of bacterial cells. dot immunoassay with ppc labeled with colloid gold was effective in testing cattle, rabbit, and human sera for antibrucella antibodies. the proposed test system is simple, economic, highly sensitive and specific, and requires no expensive equipmen ... | 1999 | 10234933 |
| structure and function prediction of the brucella abortus p39 protein by comparative modeling with marginal sequence similarities. | a methodology is proposed to solve a difficult modeling problem related to the recently sequenced p39 protein. this sequence shares no similarity with any known 3d structure, but a fold is proposed by several threading tools. the difficulty in aligning the target sequence on one of the proposed template structures is overcome by combining the results of several available prediction methods and by refining a rational consensus between them. in silico validation of the obtained model and a prelimi ... | 1999 | 10235622 |
| low prevalence of antibodies against the zoonotic agents brucella abortus, leptospira spp., streptococcus suis serotype ii, hantavirus, and lymphocytic choriomeningitis virus among veterinarians and pig farmers in the southern part of the netherlands. | serum samples from 102 veterinarians and 191 pig farmers from the southern part of the netherlands were investigated for antibodies against brucella abortus, leptospira spp, streptococcus suis serotype ii, hantavirus (hv), and lymphocytic choriomeningitis virus (lcmv). all samples were collected in 1993 and stored until this study was performed. the prevalence of antibodies against b.abortus in veterinarians (4.5%) was significantly higher (p = 0.01) than in pig farmers (0%). none of the veterin ... | 1999 | 10321013 |
| distribution of a nocardia brasiliensis catalase gene fragment in members of the genera nocardia, gordona, and rhodococcus. | an immunodominant protein from nocardia brasiliensis, p61, was subjected to amino-terminal and internal sequence analysis. three sequences of 22, 17, and 38 residues, respectively, were obtained and compared with the protein database from genbank by using the blast system. the sequences showed homology to some eukaryotic catalases and to a bromoperoxidase-catalase from streptomyces violaceus. its identity as a catalase was confirmed by analysis of its enzymatic activity on h2o2 and by a double-s ... | 1999 | 10325357 |
| pcr assay for diagnosis of human brucellosis. | | 1999 | 10328689 |
| molecular characterization of a brucella species large dna fragment deleted in brucella abortus strains: evidence for a locus involved in the synthesis of a polysaccharide. | a brucella melitensis 16m dna fragment of 17,119 bp, which contains a large region deleted in b. abortus strains and dna flanking one side of the deletion, has been characterized. in addition to the previously identified omp31 gene, 14 hypothetical genes have been identified in the b. melitensis fragment, most of them showing homology to genes involved in the synthesis of a polysaccharide. considering that 10 of the 15 genes are missing in b. abortus and that all the polysaccharides described in ... | 1999 | 10338472 |
| acute clinical disease in cats following infection with a pathogenic strain of bartonella henselae (lsu16). | bartonella henselae is the causative agent of human cat scratch disease as well as several serious sequelae of infections, including bacillary angiomatosis and bacillary peliosis. conflicting reports describe the pathogenesis of b. henselae in the cat. in this study, we characterized a strain of b. henselae termed lsu16. this strain was isolated on rabbit blood agar from a naturally infected 10-month-old female cat during a recurrent episode of bacteremia. the bacterial species was confirmed by ... | 1999 | 10338522 |
| evaluation of a fluorescence-polarization assay for the diagnosis of bovine brucellosis in méxico. | a homogeneous fluorescence-polarization assay (fpa) was used for the serological diagnosis of bovine brucellosis in méxico. the assay uses o-polysaccharide prepared from brucella abortus lipoplysaccharide (20-30 kda) conjugated with fluorescein isothiocyanate as a tracer. to measure the fluorescence polarization, a fpm-1 fluorescence-polarization analyzer was used with the procedure described by nielsen et al. (1996b). a cut-off value of 90 millipolarization (mp) units was used for testing 560 b ... | 1999 | 10343334 |
| the serodiagnosis of infections caused by verocytotoxin-producing escherichia coli. | patients with haemolytic uraemic syndrome (hus) and haemorrhagic colitis (hc) produce serum antibodies to the lipopolysaccharides (lps) of escherichia coli o157 and certain other e. coli serogroups. patients may also make salivary antibodies to the lps of e. coli o157. serological tests based on these antibodies can be used to provide evidence of infection in the absence of culturable vtec or the toxins they produce. serum antibodies to lps persist for several months following onset of disease, ... | 1999 | 10347867 |
| lysosomal accumulation and recycling of lipopolysaccharide to the cell surface of murine macrophages, an in vitro and in vivo study. | in this study, we detailed in a time-dependent manner the trafficking, the recycling, and the structural fate of brucella abortus lps in murine peritoneal macrophages by immunofluorescence, elisa, and biochemical analyses. the intracellular pathway of b. abortus lps, a nonclassical endotoxin, was investigated both in vivo after lps injection in the peritoneal cavity of mice and in vitro after lps incubation with macrophages. we also followed lps trafficking after infection of macrophages with b. ... | 1999 | 10352299 |
| degradation of japanese encephalitis virus by neutrophils. | the ability of neutrophils to degrade the phagocytosed japanese encephalitis (je) virion, via triggering of the respiratory burst and generation of toxic radicals has been investigated. jev or jev-induced macrophage derived factor (mdf) induces increase in intracellular oxidative signals with generation of superoxide anion (o2-), via activation of cytosolic nadph and subsequent formation of hydrogen peroxide, with maximum activity on day 7 post infection. the response was sensitive to anti-mdf a ... | 1999 | 10365083 |
| the mdoc gene of escherichia coli encodes a membrane protein that is required for succinylation of osmoregulated periplasmic glucans. | osmoregulated periplasmic glucans (opgs) of escherichia coli are anionic oligosaccharides that accumulate in the periplasmic space in response to low osmolarity of the medium. their anionic character is provided by the substitution of the glucosidic backbone by phosphoglycerol originating from the membrane phospholipids and by succinyl residues from unknown origin. a phosphoglycerol-transferase-deficient mdob mutant was subjected to tn5 transposon mutagenesis, and putative mutant clones were scr ... | 1999 | 10368134 |
| biosafety of brucella abortus strain rb51 for vaccination of mature bulls and pregnant heifers. | to determine shedding and colonization profiles in mature sexually intact bulls and pregnant heifers after vaccination with a standard calfhood dose of brucella abortus strain rb51 (srb51). | 1999 | 10376900 |
| early events in the pathogenesis of avian salmonellosis. | salmonellae are gastrointestinal pathogens of man and animals. however, strains that are host-specific avian pathogens are often avirulent in mammals, and those which are nonspecific are commensal in poultry. the objective of this study was to determine whether host specificity was exhibited by bacterial abilities to invade epithelial cells or resist leukocyte killing. in this study, leukocytes isolated from humans and chickens were used to kill salmonella in vitro. both salmonella pullorum, an ... | 1999 | 10377142 |
| comparison of the dot-immunobinding assay with the serum agglutination test, the rose bengal plate test and the milk ring test for the detection of brucella antibodies in bovine sera and milk. | in this study, brucella antibodies in bovine sera and milk were detected using the dot-immunobinding assay (dia), the serum agglutination test (sat), the rose bengal plate test (rbpt) and the milk ring test (mrt). for this purpose, a total of 116 paired blood and milk samples collected at the same time from 56 aborted and from 60 healthy dairy cows was examined. in dia, a nitrocellulose membrane (ncm) was used as the solid phase. antigen adsorbed on the ncm was extracted from brucella abortus s9 ... | 1999 | 10379238 |
| effects of the lipopolysaccharide-protein complex and crude capsular antigens of pasteurella multocida serotype a on antibody responses and delayed type hypersensitivity responses in the chicken. | the effects of the lipopolysaccharide-protein complex (lps) and crude capsular antigen (cca) prepared from pasteurella multocida serotype a isolated from a duck in the philippines, on antibody responses to sheep red blood cells (srbc) and brucella abortus (ba) and delayed type hypersensitivity (dth) responses to bovine serum albumin (bsa) in the chickens were studied. chickens injected subcutaneously with lps and cca at 1 and 2 weeks of age and immunized intravenously with the mixed antigens of ... | 1999 | 10379953 |
| development of primers to o-antigen biosynthesis genes for specific detection of escherichia coli o157 by pcr. | the chemical composition of each o-antigen subunit in gram-negative bacteria is a reflection of the unique dna sequences within each rfb operon. by characterizing dna sequences contained with each rfb operon, a diagnostic serotype-specific probe to escherichia coli o serotypes that are commonly associated with bacterial infections can be generated. recently, from an e. coli o157:h7 cosmid library, o-antigen-positive cosmids were identified with o157-specific antisera. by using the cosmid dnas as ... | 1999 | 10388689 |
| comparative efficacies of liposomal amikacin (mikasome) plus oxacillin versus conventional amikacin plus oxacillin in experimental endocarditis induced by staphylococcus aureus: microbiological and echocardiographic analyses. | optimal treatment strategies for serious infections caused by staphylococcus aureus have not been fully characterized. the combination of a beta-lactam plus an aminoglycoside can act synergistically against s. aureus in vitro and in vivo. mikasome, a new liposome-encapsulated formulation of conventional amikacin, significantly prolongs serum half-life (t1/2) and increases the area under the concentration-time curve (auc) compared to free amikacin. microbiologic efficacy and left ventricular func ... | 1999 | 10390232 |
| use of recombinant flagellin protein as a tracer antigen in a fluorescence polarization assay for diagnosis of leptospirosis. | the objective of the present study was to investigate the usefulness of a recombinant flagellar protein, flab, of leptospira interrogans serovar pomona in the serodiagnosis of leptospirosis by the fluorescence polarization assay (fpa). the recombinant protein flab was purified to homogeneity by a combination of nickel-nitriloacetic acid agarose chromatography, electrophoresis, and electroelution. purified flab was labeled with fluorescein isothiocyanate (fitc). western blotting was performed by ... | 1999 | 10391870 |
| conservation of expression and n-terminal sequences of the pasteurella haemolytica 31-kilodalton and pasteurella trehalosi 29-kilodalton periplasmic iron-regulated proteins. | this study examined the conservation of expression of a 31-kda iron-regulated protein by serotypes of pasteurella haemolytica and pasteurella trehalosi associated with pasteurellosis of cattle and sheep. a polyclonal antibody prepared against the purified 31-kda periplasmic iron-regulated protein from p. haemolytica serotype a1 showed that all p. haemolytica serotypes expressed similar 31-kda proteins with identical n-terminal sequences, whereas p. trehalosi serotypes expressed immunologically d ... | 1999 | 10391874 |
| brucella outer membrane lipoproteins share antigenic determinants with bacteria of the family rhizobiaceae. | brucellae have been reported to be phylogenetically related to bacteria of the family rhizobiaceae. in the present study, we used a panel of monoclonal antibodies (mabs) to brucella outer membrane proteins (omps) to determine the presence of common omp epitopes in some representative bacteria of this family, i.e., ochrobactrum anthropi, phyllobacterium rubiacearum, rhizobium leguminosarum, and agrobacterium tumefaciens, and also in bacteria reported to serologically cross-react with brucella, i. ... | 1999 | 10391877 |
| glucose transport in the extremely thermoacidophilic sulfolobus solfataricus involves a high-affinity membrane-integrated binding protein. | the archaeon sulfolobus solfataricus grows optimally at 80 degrees c and ph 2.5 to 3.5 on carbon sources such as yeast extracts, tryptone, and various sugars. cells rapidly accumulate glucose. this transport activity involves a membrane-bound glucose-binding protein that interacts with its substrate with very high affinity (kd of 0. 43 microm) and retains high glucose affinity at very low ph values (as low as ph 0.6). the binding protein was extracted with detergent and purified to homogeneity a ... | 1999 | 10400586 |
| biosafety and antibody responses of adult bison bulls after vaccination with brucella abortus strain rb51. | to evaluate clearance, antibody responses, potential shedding, and histologic lesions in reproductive tissues of adult bison bulls after vaccination with brucella abortus strain rb51. | 1999 | 10407488 |
| genetic characterization of a tn5-disrupted glycosyltransferase gene homolog in brucella abortus and its effect on lipopolysaccharide composition and virulence. | we constructed a rough mutant of brucella abortus 2308 by transposon (tn5) mutagenesis. neither whole cells nor extracted lipopolysaccharide (lps) from this mutant, designated ra1, reacted with a brucella o-side-chain-specific monoclonal antibody (mab), bru-38, indicating the absence of o-side-chain synthesis. compositional analyses of lps from strain ra1 showed reduced levels of quinovosamine and mannose relative to the levels in the parental, wild-type strain, 2308. we isolated dna flanking th ... | 1999 | 10417145 |
| early acidification of phagosomes containing brucella suis is essential for intracellular survival in murine macrophages. | brucella suis is a facultative intracellular pathogen of mammals, residing in macrophage vacuoles. in this work, we studied the phagosomal environment of these bacteria in order to better understand the mechanisms allowing survival and multiplication of b. suis. intraphagosomal ph in murine j774 cells was determined by measuring the fluorescence intensity of opsonized, carboxyfluorescein-rhodamine- and oregon green 488-rhodamine-labeled bacteria. compartments containing live b. suis acidified to ... | 1999 | 10417172 |
| interaction of brucella abortus lipopolysaccharide with major histocompatibility complex class ii molecules in b lymphocytes. | lipopolysaccharide (lps), a major amphiphilic molecule located at the outer membrane of gram-negative bacteria, is a potent antigen known to induce specific humoral immune responses in infected mammals. lps has been described as a polyclonal activator of b lymphocytes, triggering the secretion of antibodies directed against distinct sugar epitopes of the lps chain. but, how lps is handled by b cells remains to be fully understood. this task appears to be essential for a better knowledge of the a ... | 1999 | 10417173 |
| role of tolr n-terminal, central, and c-terminal domains in dimerization and interaction with tola and tolq. | the tol-pal system of escherichia coli is a multiprotein system involved in maintaining the cell envelope integrity and is necessary for the import of some colicins and phage dna into the bacterium. it is organized into two complexes, one near the outer membrane between tolb and pal and one in the cytoplasmic membrane between tola, tolq, and tolr. in the cytoplasmic membrane, all of the tol proteins have been shown to interact with each other. cross-linking experiments have shown that the tola t ... | 1999 | 10419942 |
| improved method for purification of bacterial dna from bovine milk for detection of brucella spp. by pcr. | different methods of extraction of bacterial dna from bovine milk to improve the direct detection of brucella by pcr were evaluated. we found that the use of a lysis buffer with high concentrations of tris, edta, and nacl, high concentrations of sodium dodecyl sulfate and proteinase k, and high temperatures of incubation was necessary for the efficient extraction of brucella dna. the limit of detection by pcr was 5 to 50 brucella cfu/ml of milk. | 1999 | 10427076 |
| interleukin-12-secreting fibroblasts are more efficient than free recombinant interleukin-12 in inducing the persistent resistance to mycobacterium avium complex infection. | to determine whether the paracrine secretion of interleukin-12 (il-12) can efficiently stimulate the resistance to mycobacterium avium complex (mac) infection, 3t3 fibroblasts were stably transfected to secrete il-12 (480 u/106 cells/48 hr) and their effect on mac infection was investigated in genetically susceptible balb/c mice, compared with that of free recombinant il-12 (ril-12). injection with il-12-secreting fibroblasts (3t3-il-12) during intranasal infection with mac resulted in a signifi ... | 1999 | 10447770 |
| down-regulation of th2 responses by brucella abortus, a strong th1 stimulus, correlates with alterations in the b7.2-cd28 pathway. | down-regulation of the th2-like response induced by ovalbumin-alum (ova/alum) immunization by heat-killed brucella abortus was not reversed by anti-il-12 antibody treatment or in gamma interferon (ifn-gamma) knockout mice, suggesting that induction of th1 cytokines was not the only mechanism involved in the b. abortus-mediated inhibition of the th2 response to ova/alum. the focus of this study was to determine whether an alternative pathway involves alteration in expression of costimulatory mole ... | 1999 | 10456882 |
| outer membrane proteins omp10, omp16, and omp19 of brucella spp. are lipoproteins. | the deduced sequences of the omp10, omp16, and omp19 outer membrane proteins of brucella spp. contain a potential bacterial lipoprotein processing sequence. after extraction with triton x-114, these three proteins partitioned into the detergent phase. processing of the three proteins is inhibited by globomycin, a specific inhibitor of lipoprotein signal peptidase. the three proteins were radioimmunoprecipitated from [(3)h]palmitic acid-labeled brucella abortus lysates with monoclonal antibodies. ... | 1999 | 10456959 |
| differentiation of hard-to-type bacterial strains by rna mismatch cleavage. | many bacteria are difficult to subtype due to high genetic relatedness. in the cases of pathogens of medical or veterinary importance, subtyping is an essential tool of epidemiologists. this report describes a method for molecular subtyping based on the detection of point mutations without dna sequencing or specialized equipment. the method, known as rna mismatch cleavage, hybridizes rna transcripts derived from pcr-amplified dna, with a control rna transcript followed by rnase cleavage at point ... | 1999 | 10457839 |
| fluorescence polarization assay: application to the diagnosis of bovine brucellosis in argentina. | a homogeneous fluorescence polarization assay (fpia) for detection of bovine antibody to brucella abortus was validated in argentina sera were defined based on their reactivity in the buffered antigen plate agglutination test (bpat) and the competitive enzyme immunoassay (celisa). sera negative in these tests were collected from farms without evidence of brucellosis (n=733). sera positive in the two tests were collected from cattle on farms from which b. abortus was isolated from at least one an ... | 1999 | 10458638 |
| bacterial dna methylation: a cell cycle regulator? | | 1999 | 10464180 |
| detection of antibodies to brucella cytoplasmic proteins in the cerebrospinal fluid of patients with neurobrucellosis. | the diagnosis of human neurobrucellosis usually relies on the detection of antibodies to brucella lipopolysaccharide (lps) in cerebrospinal fluid (csf) by agglutination tests or enzyme-linked immunosorbent assay (elisa). here we describe the detection of immunoglobulin g (igg) to cytoplasmic proteins (cp) of brucella spp. by elisa and western blotting in seven csf samples from five patients with neurobrucellosis. while igg to cp (titers of 200 to 12, 800) and igg to lps (800 to 6,400) were found ... | 1999 | 10473531 |
| identification of an is711 element interrupting the wboa gene of brucella abortus vaccine strain rb51 and a pcr assay to distinguish strain rb51 from other brucella species and strains. | brucella abortus vaccine strain rb51 is a natural stable attenuated rough mutant derived from the virulent strain 2308. the genetic mutations that are responsible for the roughness and the attenuation of strain rb51 have not been identified until now. also, except for an assay based on pulsed-field gel electrophoresis, no other simple method to differentiate strain rb51 from its parent strain 2308 is available. in the present study, we demonstrate that the wboa gene encoding a glycosyltransferas ... | 1999 | 10473532 |
| competitive enzyme immunoassay for diagnosis of human brucellosis. | the methods commonly used for human brucellosis serological testing are agglutination tests and the complement fixation test (cft). among the newer serological tests, primary binding assays were developed to improve sensitivity and specificity. the competitive enzyme immunoassay (celisa) for the detection of serum antibody to brucella is a multispecies assay which appears to be capable of differentiating vaccinal and cross-reacting antibodies from antibodies elicited by field infection in cattle ... | 1999 | 10488186 |
| evidence for immunosuppression associated with jembrana disease virus infection of cattle. | jembrana disease virus (jdv) is a newly recognised bovine lentivirus causing an acute disease syndrome in bali cattle (bos javanicus) in indonesia. we evaluated the effect of jdv infection on the antibody response to chicken ovalbumin (cova) and brucella abortus strain 19 in bali cattle. in infected cattle the igg and igm response to cova was suppressed and delayed and the igg response to b. abortus strain 19 was delayed. the results indicate that the humoral immune response is suppressed and de ... | 1999 | 10501175 |
| [use of a recombinant protein from brucella abortus for the diagnosis of brucellosis in different animal species]. | | 1999 | 10509409 |
| mechanism of serum resistance among brucella abortus isolates. | it was shown in this study that complement-resistant brucella abortus used were unable to activate complement in the absence of specific antibody. complement-resistant isolates possessed o-antigen, but complement-sensitive organisms used are o-antigen deficient. since b. abortus lps does not activate the alternative pathway of complement, we concluded that activation of bovine complement must be due to some other mechanism. in this study, it was shown that bovine c1 binds to the outer membrane p ... | 1999 | 10510042 |
| human and animal epidemic of yersinia enterocolitica o:9, 1989-1997, auvergne, france. | yersinia enterocolitica o:9 infections were reported in auvergne in 1988 to 1989, while brucellosis due to brucella abortus was almost eliminated. the serologic cross-reactions between the two bacteria complicated the diagnosis of brucellosis cases. in 1996, human cases of yersinia enterocolitica o:9 infection were detected, with a peak incidence of 12 cases. veterinary surveillance could have predicted the emergence of this disease in humans. | 1999 | 10511531 |
| epitopes for chicken monoclonal antibodies in spleens of selected japanese quail lines. | a line of japanese quail selected for high plasma cholesterol is highly susceptible to diet-induced atherosclerosis. lymphocyte epitopes recognized by mouse anti-chicken monoclonal antibodies (c-mab), tcr-1, tcr-2, tcr-3. cd-3, cd-4, cd-8, and bu-1a/b were reacted with spleens from quail selected for high (hl) and low (ll) plasma total cholesterol and their nonselected controls (cl). cross reactivity to c-mab and effect of line and gender were immunohistochemically evaluated. chicken spleens wer ... | 1999 | 10512460 |
| detection of brucellae in blood cultures. | | 1999 | 10523530 |
| invasion of human coronary artery cells by periodontal pathogens. | there is an emerging paradigm shift from coronary heart disease having a purely hereditary and nutritional causation to possibly having an infectious etiology. recent epidemiological studies have shown a correlation between periodontal disease and coronary heart disease. however, to date, there is minimal information as to the possible disease mechanisms of this association. it is our hypothesis that invasion of the coronary artery cells by oral bacteria may start and/or exacerbate the inflammat ... | 1999 | 10531230 |
| protection of mice against brucellosis by vaccination with brucella melitensis wr201(16mdeltapurek). | human brucellosis can be acquired from infected animal tissues by ingestion, inhalation, or contamination of the conjunctiva or traumatized skin by infected animal products. a vaccine to protect humans from occupational exposure or from zoonotic infection in areas where the disease is endemic would reduce an important cause of morbidity worldwide. vaccines currently used in animals are unsuitable for human use. we tested a live, attenuated, purine-auxotrophic mutant strain of brucella melitensis ... | 1999 | 10531243 |
| laccase protects cryptococcus neoformans from antifungal activity of alveolar macrophages. | while laccase of cryptococcus neoformans is implicated in the virulence of the organism, our recent studies showing absence of melanin in the infected mouse brain has led us to a search for alternative roles for laccase in cryptococcosis. we investigated the role of laccase in protection of c. neoformans against murine alveolar macrophage (am)-mediated antifungal activity by using a pair of congenic laccase-positive (2e-tuc) and laccase-deficient (2e-tu) strains. the laccase-positive cells with ... | 1999 | 10531264 |
| identification of regions of the chromosome of neisseria meningitidis and neisseria gonorrhoeae which are specific to the pathogenic neisseria species. | neisseria meningitidis and neisseria gonorrhoeae give rise to dramatically different diseases. their interactions with the host, however, do share common characteristics: they are both human pathogens which do not survive in the environment and which colonize and invade mucosa at their port of entry. it is therefore likely that they have common properties that might not be found in nonpathogenic bacteria belonging to the same genetically related group, such as neisseria lactamica. their common p ... | 1999 | 10531275 |
| the outer membrane of brucella ovis shows increased permeability to hydrophobic probes and is more susceptible to cationic peptides than are the outer membranes of mutant rough brucella abortus strains. | the permeability of the outer membrane (om) to hydrophobic probes and its susceptibility to bactericidal cationic peptides were investigated for natural rough brucella ovis and for mutant rough brucella abortus strains. the om of b. ovis displayed an abrupt and faster kinetic profile than rough b. abortus during the uptake of the hydrophobic probe n-phenyl-naphthylamine. b. ovis was more sensitive than rough b. abortus to the action of cationic peptides. bactenecins 5 and 7 induced morphological ... | 1999 | 10531286 |
| the adjuvant effect of a single dose of interleukin-12 on murine immune responses to live or killed brucella abortus strain rb51. | this study was designed to determine if a single 0.5 microg administration of recombinant murine interleukin-12 (il-12) would influence immune responses of mice vaccinated with live or killed brucella abortus strain rb51 (srb51). mice were vaccinated intraperitoneally with 5 x 10(8) cfu of live or gamma-irradiated srb51 bacteria alone, or in combination with 0.5 microg of il-12. control mice received saline or 0.5 microg of il-12. serologic responses and spleen weights after vaccination were gre ... | 1999 | 10534009 |
| attenuation of virulence in mycobacterium tuberculosis expressing a constitutively active iron repressor. | iron is an essential nutrient for the survival of most organisms and has played a central role in the virulence of many infectious disease pathogens. mycobacterial ider is an iron-dependent repressor that shows 80% identity in the functional domains with its corynebacterial homologue, dtxr (diphtheria toxin repressor). we have transformed mycobacterium tuberculosis with a vector expressing an iron-independent, positive dominant, corynebacterial dtxr hyperrepressor, dtxr(e175k). western blots of ... | 1999 | 10536010 |
| isolation of polymyxin b-susceptible mutants of burkholderia pseudomallei and molecular characterization of genetic loci involved in polymyxin b resistance. | burkholderia pseudomallei is a gram-negative bacterium that causes the disease known as melioidosis. this pathogen is endemic to southeast asia and northern australia and is particularly problematic in northeastern thailand. it has been previously reported that b. pseudomallei is resistant to the killing action of cationic antimicrobial peptides, including human neutrophil peptide, protamine sulfate, poly-l-lysine, magainins, and polymyxins. recently, we have also found that the virulent clinica ... | 1999 | 10543742 |
| antigen receptor-induced activation and cytoskeletal rearrangement are impaired in wiskott-aldrich syndrome protein-deficient lymphocytes. | the wiskott-aldrich syndrome protein (wasp) has been implicated in modulation of lymphocyte activation and cytoskeletal reorganization. to address the mechanisms whereby wasp subserves such functions, we have examined wasp roles in lymphocyte development and activation using mice carrying a was null allele (was(-)(/)(-)). enumeration of hemopoietic cells in these animals revealed total numbers of thymocytes, peripheral b and t lymphocytes, and platelets to be significantly diminished relative to ... | 1999 | 10544204 |
| complement fixation test to assess humoral immunity in cattle and sheep vaccinated with brucella abortus rb51. | the live attenuated brucella abortus strain rb51 is a rifampin-resistant, lipopolysaccharide (lps) o-chain-deficient mutant of virulent b. abortus 2308. the reduced o-chain content in rb51 prevents this bacterium from inducing antibodies detectable by the conventional serologic tests for bovine brucellosis diagnosis that mainly identify antibodies to lps. the absence of available serologic tests for rb51 also complicates the diagnosis of possible rb51 infections in humans exposed to this strain. ... | 1999 | 10548564 |
| genetic line and major histocompatibility complex effects on primary and secondary antibody responses to t-dependent and t-independent antigens. | the effects of mhc and nonmhc (background) genetics on the kinetics of primary and secondary antibody responses to t-cell-dependent (srbc) and t-cell-independent [brucella abortus (ba)] antigens were investigated. eight genetic groups were represented, with four homozygous mhc haplotypes [b1-irgatlow (irgat = immune response to gat locus); b1-irgathigh; b19-ir-gatlow; b19-irgathigh] on two genetic backgrounds, the s1 and g lines. birds were injected simultaneously with ba and srbc at 4 and 7 wk ... | 1999 | 10560823 |
| the brucella abortus host factor i (hf-i) protein contributes to stress resistance during stationary phase and is a major determinant of virulence in mice. | brucella abortus is a facultative intracellular pathogen that causes abortion and infertility in domestic animals and a severe debilitating febrile illness in humans. the mechanisms that this highly successful intracellular pathogen uses to adapt to, and survive within, the harsh intracellular environment of the host macrophage are presently unknown. maintenance of the stationary phase growth state has been proposed to be critical for the virulence of several mammalian pathogens, but analysis of ... | 1999 | 10564509 |
| detection by pcr of neospora caninum in fetal tissues from spontaneous bovine abortions. | the routine diagnosis of neospora caninum abortion is based upon histopathologic changes in fetal tissues and identification of tissue parasites by immunohistochemistry. confirmation of n. caninum infection by immunohistochemistry has low sensitivity. in the present study, we examined the utility of pcr in detecting n. caninum infection in fetal tissues from spontaneous bovine abortion. dna was obtained from fresh and formalin-fixed tissues from 61 bovine fetuses submitted for abortion diagnosis ... | 1999 | 10565932 |
| posttreatment follow-up of brucellosis by pcr assay. | in order to evaluate the usefulness of a peripheral blood pcr assay in the posttreatment follow-up of brucellosis, a cohort of 30 patients was studied by means of blood cultures, rose bengal, seroagglutination, coombs' antibrucella tests, and pcr assay at the time of diagnosis, at the end of treatment, and 2, 4, and 6 months later. of the 29 patients whose pcr assays were initially positive, 28 (96.5%) were negative at the conclusion of the treatment. pcr was positive for the two patients who ha ... | 1999 | 10565954 |
| development and evaluation of a rapid dipstick assay for serodiagnosis of acute human brucellosis. | a dipstick assay for the detection of brucella-specific immunoglobulin m antibodies was evaluated with 707 sera from 247 laboratory-confirmed brucellosis patients and 342 control sera from brucellosis-free individuals. these sera were collected from six different countries. the assay was found to be highly sensitive and specific. in addition, the test is easy to use and does not require specialized training or equipment, and the components are stable without a requirement for refrigeration. all ... | 1999 | 10565959 |
| induction and regulation of th1-inducing cytokines by bacterial dna, lipopolysaccharide, and heat-inactivated bacteria. | th1 immune responses, characterized by production of gamma interferon (ifn-gamma), are associated with protective immunity to viruses and intracellular bacteria. heat-killed brucella abortus promotes secretion of th1-inducing cytokines such as interleukin-12 (il-12) and ifn-gamma and has been used as a carrier to induce th1 responses to vaccines. to explore which bacterial constituents could mediate this response and how it is regulated, murine spleen cells were cultured with b. abortus derived ... | 1999 | 10569735 |
| constitutive and inducible expression of green fluorescent protein in brucella suis. | a gene fusion system based on plasmid pbbr1mcs and the expression of green fluorescent protein was developed for brucella suis, allowing isolation of constitutive and inducible genes. bacteria containing promoter fusions of chromosomal dna to gfp were visualized by fluorescence microscopy and examined by flow cytometry. twelve clones containing gene fragments induced inside j774 murine macrophages were isolated and further characterized. | 1999 | 10569794 |