Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
immunologic responses of domestic and bighorn sheep to a multivalent pasteurella haemolytica vaccine.the efficacy of a pasteurella haemolytica vaccine (serotypes a1, a2, and t10) to induce humoral antibodies and alter colonization of the upper respiratory tract by related p. haemolytica spp. strains was evaluated in 10 bighorn (ovis canadensis canadensis) and 10 domestic (ovis aries) sheep. sheep of each species were divided into five pairs based on age and history of respiratory disease. one sheep in each pair was vaccinated twice 2 wk apart with 2 ml of vaccine (vac group) and the remaining a ...199910231755
critica: coding region identification tool invoking comparative analysis.gene recognition is essential to understanding existing and future dna sequence data. critica (coding region identification tool invoking comparative analysis) is a suite of programs for identifying likely protein-coding sequences in dna by combining comparative analysis of dna sequences with more common noncomparative methods. in the comparative component of the analysis, regions of dna are aligned with related sequences from the dna databases; if the translation of the aligned sequences has gr ...199910331277
evidence of pasteurella haemolytica linked immune complex disease in natural and experimental models.the pathogenesis of bovine pneumonic pasteurellosis is not completely understood, and studies have not established that pasteurella haemolytica a1 (ph1) virulence is exclusively responsible for the development of acute pulmonary lesions. the purpose of this investigation was to determine if immune complex disease is involved in the pathogenesis of bovine pneumonic pasteurellosis. a retrospective immunohistologic study of lung tissue from natural cases of bovine pneumonic pasteurellosis (44) as p ...199910089159
identification of immunogenic, surface-exposed outer membrane proteins of pasteurella haemolytica serotype 1.pasteurella haemolytica serotype 1 (s1) is the bacterium most frequently recovered from the lungs of cattle that have succumbed to shipping fever pneumonia. p. haemolytica outer membrane proteins (omps) are important immunogens in the development of resistance to pneumonic pasteurellosis. the purpose of this study was to identify the repertoire of immunogenic, surface-exposed p. haemolytica (s1) omps, that could be important in the development of protective immunity. we determined surface exposu ...199910189196
use of tunel staining to detect apoptotic cells in the lungs of cattle experimentally infected with pasteurella haemolytica.lung sections taken from calves with experimental pasteurella haemolytica respiratory infection exhibited increased numbers of tunel positive cells with time after challenge. this finding suggests that p. haemolytica, or toxins and other components released by the organism, induces apoptosis in bovine leukocytes in vivo. by so doing this might impair host defense and contribute in part to the severe pneumonia that characterizes bovine pasteurellosis.199910455008
adjuvant and protective properties of native and recombinant bordetella pertussis adenylate cyclase toxin preparations in mice.bordetella pertussis produces a cell-invasive adenylate cyclase toxin which is synthesised from the cyaa gene as an inactive protoxin that is post-translationally activated by the product of the cyac gene. purified active and inactive cyaa proteins were prepared from b. pertussis or from recombinant escherichia coli expressing both cyaa and cyac genes or the cyaa gene alone. respectively. in addition, a hybrid toxin (hyb2) in which an internal region of cyaa had been replaced with the analogous ...199910225286
molecular cloning of the pasteurella haemolytica poma gene and identification of bovine antibodies against poma surface domains.the gene (poma) encoding poma, an ompa-like major outer membrane protein of the bovine respiratory pathogen pasteurella haemolytica, was cloned, and its nucleotide sequence was determined. the deduced amino acid sequence of poma has significant identity with the sequences of other ompa family proteins. absorption of three different bovine immune sera with whole p. haemolytica cells resulted in a reduction of bovine immunoglobulin g reactivity with recombinant poma in western immunoblots, suggest ...199910456961
clinical and microbiological study of an otitis media outbreak in calves in a dairy herd.on a dairy farm, otitis media was diagnosed in 64 suckler calves (21.8%) during a study period of 2 years, and in 10 calves (3.4%) in the third year. the inflammation was unilateral in 63 and bilateral in 11 calves. the affected calves were dull, lacked appetite, were pyrexic and displayed drooping ear or ears and tilted heads with purulent discharge exuding from the external ear canal. of the affected animals, 56 (87.5%) were aged between 3 and 8 weeks. morbidity was higher during the calving s ...199910337235
the leukotoxin of pasteurella haemolytica binds to beta(2) integrins on bovine leukocytes.the putative receptor proteins of pasteurella haemolytica leukotoxin were isolated from bovine polymorphonuclear neutrophil lysate by affinity chromatography on a leukotoxin-specific monoclonal antibody column to which the leukotoxin was pre-bound. sds-page of the purified proteins showed four bands at 180 kda, 170 kda, 150 kda and 95 kda, in addition to the expected 102-kda leukotoxin band and a series of bands with molecular masses lower than 102 kda representing the disintegrated leukotoxin. ...199910481101
lipopolysaccharide complexes with pasteurella haemolytica leukotoxin.the presence of lipopolysaccharide (lps) in gram-negative bacterial repeats-in-toxin (rtx) toxin preparations, as well as the harsh conditions required to remove it, suggests that lps may complex with rtx toxins. concentrated culture supernatant (ccs) preparations of the rtx toxin pasteurella haemolytica leukotoxin (lkt) contained lkt and lps as the most prominent components, with lkt and lps constituting approximately 30 and 50% of the density of the silver-stained fraction on sodium dodecyl su ...199910338500
cytokine profiles following interaction between bovine alveolar macrophages and pasteurella haemolytica.pasteurella haemolytica is a gram negative bacterium frequently isolated from the lungs of calves suffering from a fibrinous pneumonic condition known as shipping fever. to understand the pathogenesis of this disease, we investigated the induction of cytokin gene expression in cultures of bovine alveolar macrophages (bam) stimulated with heat-killed p. haemolytica. northern blot analysis of total rna showed that p. haemolytica induced early, abundant, and consistent synthesis of il-1, tnf-alpha, ...199910343061
cloning and characterization of the gene encoding pasteurella haemolytica fnrp, a regulator of the escherichia coli silent hemolysin shea.a pasteurella haemolytica a1 gene was identified from a recombinant library clone that expressed hemolysis in host escherichia coli cells. the gene, designated fnrp, had sequence identity to e. coli fnr, a global transcriptional regulator of genes required for conversion to anaerobic growth. fnrp complemented anaerobic deficiencies of a fnr-null mutant strain of e. coli and increased expression of the fnr-dependent, anaerobic terminal reductase gene, frda. fnrp was purified, identified by immuno ...199910368164
serotypes and electrophoretic protein profiles of pasteurella haemolytica isolated from pneumonic ovine lungs.serotypes and sds-page protein profiles of p. haemolytica isolated from pneumonic ovine lungs were investigated. of 268 p. haemolytica isolates, 232 (86.6%) were serotypable. a total of 12 serotypes were recognized in 20 different geographic origins of central turkey. the most common serotype was a2, followed by a7, a1 and t4. serotypes a13, a14, a16 and t15 could not be detected. in sds-page, marked differences between major bands of biotype a and t strains were found. in numerical analysis of ...199910379102
serotypes of pasteurella haemolytica and pasteurella trehalosi isolated from farm animals in hungary.the biochemical and serological characteristics of 486 p. haemolytica and 31 p. trehalosi strains (517 in total) isolated from different lesions of cattle, sheep, goats, pigs and poultry were examined. a total of 476 p. haemolytica strains (97.9%) showed the characteristics typical of the former biotype a of p. haemolytica, while 10 isolates (2.1%), all from poultry, could not be biotyped. a total of 481 strains (93.0%) could be assigned to one of the 17 serotypes of p. haemolytica-p. trehalosi ...199910379234
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 ...199910391874
bovine cd18 identified as a species specific receptor for pasteurella haemolytica leukotoxin.ligand blotting of pasteurella haemolytica leukotoxin (lkt) susceptible bl3 bovine lymphoma cell membranes with lkt detected two putative receptors with mr of 95 and 100 kda, whereas no lkt binding to membrane proteins was detected for lkt non-susceptible human leukemic cells. anti-bovine cd18 and cd11a/cd18 mab recognized 95 and 100kda bands from bl3 cell membranes. cd18 isolated from bl3 cell membranes bound lkt. pre-incubation of bl3 cells with anti-bovine cd18 or cd11a/cd18 mab caused partia ...199910414364
role of phospholipase d in pasteurella haemolytica leukotoxin-induced increase in phospholipase a(2) activity in bovine neutrophils.the effects of pasteurella haemolytica leukotoxin (lkt) on the activity of phospholipase d (pld) and the regulatory interaction between pld and phospholipase a(2) (pla(2)) were investigated in assays using isolated bovine neutrophils labeled with tritiated phospholipid substrates of the two enzymes. exposure of [(3)h]lysophosphatidylcholine-labeled neutrophils to lkt caused concentration- and time-dependent production of phosphatidic acid (pa), the product of pld. lkt-induced generation of pa wa ...199910417136
postantibiotic and physiological effects of tilmicosin, tylosin, and apramycin at subminimal and suprainhibitory concentrations on some swine and bovine respiratory tract pathogens.the antimicrobial activity of tilmicosin, tylosin, and apramycin on some important gram-negative swine and bovine pathogens namely, pasteurella multocida, pasteurella haemolytica, bordetella bronchiseptica, and actinobacillus pleuropneumoniae were studied in vitro. the effect of minimal inhibitory concentrations (mics) and sub-mics (1/4, 1/2 mic) on bacterial growth was evaluated. the presence of tilmicosin, tylosin and apramycin in the medium decreased the rate of growth of the bacterial strain ...199910461841
in situ expression of intercellular adhesion molecule-1 (icam-1) mrna in calves with acute pasteurella haemolytica pneumonia.the in situ expression of intercellular adhesion molecule-1 (icam-1) mrna in normal and pneumonic lung tissues of holstein calves with bovine leukocyte adhesion deficiency (blad) was compared with that of age-matched non-blad holstein calves by in situ hybridization. twenty-four holstein calves (both blad and non-blad) were randomly assigned to one of two experimental groups and inoculated intrabronchially with pasteurella haemolytica or pyrogen-free saline. lung tissues were collected and fixed ...199910490211
protective capacity of the pasteurella haemolytica transferrin-binding proteins tbpa and tbpb in cattle.the transferrin-binding proteins tbpa and tbpb from pasteurella haemolytica biotype a serotype 1 were tested for their ability to confer protection against experimental p. haemolytica infection when administered to calves in vaccine formulations containing one or both antigens. vaccine groups included tbpb (single immunization), tbpb (two immunizations), tbpa, tbpa+tbpb and a placebo. all animals that received tbpb had measurable antibody titres against the antigen at the time of challenge, whil ...199910502460
expression of inducible nitric oxide synthase in spontaneous bovine bronchopneumonia.the expression of inducible nitric oxide synthase (inos), major histocompatibility class ii molecules (mhc-ii), cd68, and the calcium-binding proteins s100a8 and s100a9 (also called mrp8 and mrp14, respectively) was assessed in lung tissues from cattle that succumbed to pneumonia. expression patterns of these markers were related to the types of lung lesion. inos expression was only observed in lungs infected with arcanobacterium pyogenes or pasteurella haemolytica but not in lungs from cattle w ...199910490207
seroepidemiology of undifferentiated fever in feedlot calves in western canada.the relationships between 4 bacterial and 3 viral antibody titers and morbidity (undifferentiated fever (uf)) and mortality were investigated in recently weaned beef calves. blood samples from 100 animals that required treatment for uf (cases) and 100 healthy control animals (controls) were obtained: upon arrival at the feedlot (arrival), at the time of selection as a case or control (selection), and at approximately 33 d of the feeding period (convalescent). seroconversion to pasteurella haemol ...19999919366
taxonomic relationships of the [pasteurella] haemolytica complex as evaluated by dna-dna hybridizations and 16s rrna sequencing with proposal of mannheimia haemolytica gen. nov., comb. nov., mannheimia granulomatis comb. nov., mannheimia glucosida sp. nov., mannheimia ruminalis sp. nov. and mannheimia varigena sp. nov.the present paper presents the conclusions of a polyphasic investigation of the taxonomy of the trehalose-negative [pasteurella] haemolytica complex. clusters previously identified by ribotyping and multilocus enzyme electrophoresis (mee) have been evaluated by 16s rrna sequencing and dna-dna hybridizations. results obtained by the different techniques were highly related and indicated that the [p.] haemolytica complex contains distinct genetic and phenotypic groups. at least seven species were ...199910028248
characterization of a cacag pentanucleotide repeat in pasteurella haemolytica and its possible role in modulation of a novel type iii restriction-modification system.in a previous study, a recombinant plasmid that contains a cacag pentanucleotide repeat was isolated from a pasteurella haemolytica a1 library. southern hybridization analysis using a (cacag)5probe indicated the presence of two loci that contain the pentanucleotide repeats on the genome of p.haemolytica a1. additional hybridization analyses against genomic dna from related microorganisms indicated that the repeats are only present in p.haemolytica and pasteurella trehalosi t3. the various seroty ...199910037813
the effects of dexamethasone on the response of bronchus-associated lymphoid tissue to intranasal administration of formalin-killed pasteurella haemolytica a2 in goats.a trial was conducted to observe the immediate and chronic effects in goats of dexamethasone administration on the bronchus-associated lymphoid tissue (balt) response to intranasal administration of formalin-killed pasteurella haemolytica a2. twenty-four goats were divided into four groups. those in group 1 were injected intramuscularly with 1 mg/kg dexamethasone on three consecutive days, followed by intranasal exposure to formalin-killed p. haemolytica a2 one day after the last dexamethasone t ...199910672963
occurrence and structure-function relationship of pentameric short sequence repeats in microbial genomes.it is suggested that genomes found in any form of cellular life contain potentially size-variable repetitive dna moieties. in eukaryotes, large proportions of the multi-chromosomal genome consist of various classes of repetitive dna. also in archaeal genomes, repetitive dna is encountered and, as is the case for the eukaryotes as well, little or no function is at present attributable to most of it. for prokaryotes, elegant experiments have highlighted so-called slipped strand nucleotide mispairi ...199910673001
the associations of viral and mycoplasmal antibody titers with respiratory disease and weight gain in feedlot calves.blood samples from 32 groups of calves (n = 700) were taken on arrival and after 28-35 days at the feedlot. eleven groups were housed in feedlots in ontario, and 21 groups in feedlots in alberta. serum antibody titers to bovine viral diarrhea virus (bvdv), bovine respiratory syncytial virus (brsv), parainfluenza virus type 3 (piv-3), infectious bovine rhinotracheitis virus (ibrv), mycoplasma dispar and m. bovis, plus data on bovine corona virus (bcv) from a previous study were investigated for t ...199912001336
evaluation of structural and functional alterations of circulating neutrophils in calves with experimentally induced pneumonic pasteurellosis.to determine the structural and functional alterations in circulating neutrophils that may lead to sequestration in lung microvasculature and endothelial injury in calves with experimentally induced pneumonic pasteurellosis.199910791946
cell adhesion molecules in the pathogenesis of and host defence against microbial infection.eukaryotic cell adhesion molecules (cams) are used by various cells and extracellular molecules in host defence against infection. they are involved in many processes including recognition by circulating phagocytes of a site of inflammation, transmigration through the endothelial barrier, diapedesis through basement membrane and extracellular matrix, and release of effector mechanisms at the infected site. cams involved in leucocyte-endothelial cell interaction include the selectins, integrins, ...199910694943
ultrastructure of pasteurella haemolytica-induced changes in gnotobiotic calf lung.gnotobiotic calves born and maintained in a germ-free environment until inoculated with a pathogen are model animals for studying the progression of a specific disease, such as pneumonic pasteurellosis. to investigate early progression of pneumonic pasteurellosis, we compared the ultrastructure of regions of gas-exchange in the lungs of three challenge-exposed and three uninoculated control gnotobiotic calves. three calves were inoculated endobronchially with a bolus of 7.9 x 10(10) cfu of paste ...199910685387
the production and evaluation of pasteurella haemolytica leukotoxin in the supernatant of submerged cultures in fermenters.the optimal production of p. haemolytica leukotoxin in the culture supernatant of a fluid medium is dependent on a number of factors. the leukotoxin has to be produced by using a strain that is known for its ability to produce high quantities of leukotoxin, inoculated into the most suitable type of medium at the correct culture density containing the necessary supplements and harvested after a certain growth period. the volume in which it is produced may also have an influence. two different pro ...199910689699
in vitro microbiological characterization of novel cyclic homopentapeptides, cp-101,680 and cp-163,234, for animal health use.two cyclic homopentapeptides, cp-101,680 and cp-163,234 [6a-(3',4'-dichlorophenylamino) analogs of viomycin and capreomycin, respectively], were identified as novel antibacterial agents for the treatment of animal disease, especially for livestock respiratory disease. the in vitro microbiological characterization of both cp-101,680 and cp-163,234 was carried out using their parent compounds, viomycin and capreomycin, as controls. this characterization included antibacterial spectrum, influence o ...199910656573
genomic structure of the rat major ap endonuclease gene (apex) with an adjacent putative o-sialoglycoprotease gene (prsmg1/gcpl1) and a processed apex pseudogene (apexp1).genomic sequencing and chromosomal assignment of the gene encoding rat apex nuclease, a multifunctional dna repair enzyme, were performed. an active apex gene and a processed pseudogene were isolated from a rat genomic library. the active apex gene consists of 5 exons and 4 introns spanning 2.1 kb. the putative promoter region of the apex gene lacks the typical tata box, but contains caat boxes and a cpg island having putative binding sites for several transcription factors, such as sp1, ap-2, g ...199910631378
use of a polymerase chain reaction method to detect the leukotoxin gene lkta in biogroup and biovariant isolates of pasteurella haemolytica and p trehalosi.to determine whether pasteurella haemolytica and p trehalosi isolates possess the structural gene for pasteurella leukotoxin lkta and whether beta-hemolytic activity of these isolates correlated with detection of the lkta gene.199910566816
correlation of pasteurella haemolytica leukotoxin binding with susceptibility to intoxication of lymphoid cells from various species.pasteurella haemolytica, the causative agent of shipping fever pneumonia in cattle, produces a leukotoxin (lkt) which lyses ruminant leukocytes with high efficiency but is reputed to not affect leukocytes from nonruminant species. in this study, we tested the supposition that lkt binding correlates positively with susceptibility to intoxication of susceptible isolated bovine lymphocytes and lymphoma tissue culture cells (bl3 cells) and negatively with reputed nonsusceptible equine, porcine, and ...199910569736
anionic antimicrobial peptide-lysozyme interactions in innate pulmonary immunity.the respiratory tract contains numerous antimicrobial factors necessary for normal innate pulmonary defense. although many of these molecules reside in airway surface liquid (asl) simultaneously, little information exists concerning antagonistic, additive, or synergistic interactions. since both cationic lysozyme and anionic antimicrobial peptides (ap) are found in high concentrations in asl, the purpose of this study was to assess any interaction that might affect antimicrobial activity. for th ...199910563404
detection of annexin i and iv and haptoglobin in bronchoalveolar lavage fluid from calves experimentally inoculated with pasteurella haemolytica.to determine whether annexins or haptoglobin could be detected in bronchoalveolar lavage (bal) fluid specimens obtained from calves experimentally inoculated with pasteurella haemolytica.199910566814
[mechanisms of pathogenicity and adhesion in pasteurella haemolytica].pasteurella haemolytica is one of the bacteria most commonly isolated from pneumonic cases in ruminants. some of the mechanisms and factors involved in the pathogenesis of the disease are partially documented; and the early stages of bacterial colonization have not been totally clarified. therefore a review is presented in this paper, particularly related with the mechanisms of bacterial pathogenicity responsible of pulmonary damage to ruminants, as well as a detailed analysis of the adherence p ...199910932756
diagnosis of enzootic pneumonia in danish cattle: reverse transcription-polymerase chain reaction assay for detection of bovine respiratory syncytial virus in naturally and experimentally infected cattle.a reverse transcription-polymerase chain reaction (rt-pcr) assay was developed for detection of bovine respiratory syncytial virus (brsv) in lung tissue of naturally and experimentally infected cattle. primers were selected from the gene coding the f fusion protein, which is relatively conserved among brsv isolates. the rt-pcr assay was highly specific, it yielded positive reactions only when performed on brsv-infected cell cultures or tissues. the detection limit of the rt-pcr assay was assesse ...199912968754
chronic non-progressive pneumonia of sheep in new zealand - a review of the role of mycoplasma ovipneumoniae.chronic non-progressive pneumonia (cnp) is a common disease which affects lambs in new zealand during late summer and autumn. mycoplasma ovipneumoniae can be recovered from a high proportion of lesions but it is also present in some normal lungs. bacteria, especially pasteurella haemolytica, can also be recovered from more than half the lungs of affected animals. isolates of m. ovipneumoniae are genetically heterogeneous, as demonstrated by examination of their dna or total cellular proteins, an ...199916032095
biochemical conditions for the production of polysialic acid by pasteurella haemolytica a2.the capsular polysaccharide of pasteurella haemolytica a2 consists of a linear polymer of n-acetylneuraminic acid (neu5ac) with alpha(2-8) linkages. when the bacterium was grown at 37 degrees c for 90 h in 250 ml shake flasks at 200 rpm in brain heart infusion broth (bhib), it accumulated, attaining a level of 60 microg/ml. release of this polymer was strictly regulated by the growth temperature, and above 40 degrees no production was detected. the pathway for the biosynthesis of this sialic aci ...199810052589
problems of identification in clinical microbiology exemplified by pig bite wound infections.our experience from attempts to identify bacteria isolated from boar bite/gore wounds is the background for a discussion of identification problems. some organisms, although not very common or well-known, can be identified when using commercial kits or conventional methods, provided they are sufficiently characterized, as exemplified by pasteurella aerogenes isolated from cases 1 and 2. some organisms may be wrongly identified, or not identified, by both commercial kits and conventional methods, ...19989987187
alterations in bovine platelet function and acute phase proteins induced by pasteurella haemolytica a1.platelet function was assessed by aggregometry in 10 holstein calves before and after exposure to pasteurella haemolytica (biotype a, serotype 1) by intrabronchial challenge. at 24 h after exposure the platelets had become more reactive to stimulation with known platelet agonists such as adenosine diphosphate (adp) and platelet-activating factor (paf) and the platelet aggregates that formed were more resistant to disaggregation. the activation of platelets was an early response in the challenged ...19989442932
construction of an isogenic leukotoxin deletion mutant of pasteurella haemolytica serotype 1: characterization and virulence.allelic replacement was used to generate two isogenic lkta deletion mutants of pasteurella haemolytica serotype 1 that were incapable of synthesizing leukotoxin (lkt). southern blot data confirmed that lkta sequences were absent in the two p. haemolytica deletion mutants. culture supernatants and whole cell lysates from the wild type p. haemolytica, d153 parent strain, but not the lkta deletion mutants, contained immunoreactive and bioactive leukotoxic protein. in addition, only the parent strai ...19989466945
assessment of spatial and temporal clustering of ampicillin- and tetracycline-resistant strains of pasteurella multocida and p haemolytica isolated from cattle in california.to determine whether ampicillin- and tetracycline-resistant strains of pasteurella multocida and p haemolytica isolated from california cattle with pneumonia were spatially and temporally clustered and to compare overall estimates of percentages of these isolates resistant to these antimicrobials with estimates obtained on the basis of regional and temporal information.19989540872
development and testing of a unique strain of pasteurella haemolytica for use in studies on colonization of the respiratory tract of cattle.to develop a unique strain of pasteurella haemolytica, selectable from nasopharyngeal respiratory tract secretions, that retains the ability to efficiently colonize the respiratory tract of calves.19989563625
changes in the lungs of lambs after intratracheal injection of lipopolysaccharide from pasteurella haemolytica a1.ten lambs aged 8 weeks were inoculated intratracheally through the tracheal wall with lipopolysaccharide from pasteurella haemolytica a1 and examined in chronological sequence by light and electron microscopy for pulmonary lesions. an acute fibrinopurulent pneumonia was produced, which resolved within 72 h but bore many resemblances to field cases of pneumonic pasteurellosis. sequestration of neutrophils in the capillaries of the lungs and aggregation of surfactant in the alveoli occurred rapidl ...19989573513
molecular and biochemical mechanisms of pasteurella haemolytica leukotoxin-induced cell death.pasteurella haemolytica leukotoxin (lkt) is a member of the rtx family of pore-forming toxins that kill bovine immune cells. several studies have suggested that rtx toxins kill target cells by the induction of apoptosis. in the present study, bl3 bovine leukaemia cells were exposed to lkt and assessed by molecular and flow cytometric techniques that measure different aspects of apoptotic cell death. the intoxicated cells demonstrated morphological, light scatter and hoechst 33258 staining charac ...19989895270
in vivo production of neuraminidase by pasteurella haemolytica in market stressed cattle after natural infection.pasteurella haemolytica (ph) is the most important cause of the bovine acute fibrinohemorrhagic pneumonia that occurs in market stressed calves after shipment to feedyards. recent characterization of neuraminidase production by these organisms has shown that all 16 serotypes produce an immunologically similar form of the enzyme. anti-neuraminidase antibody against pha1 and pha6 was determined in 101 2- to 5-month-old calves, on their farms of origin, at the order buyer barn (obb), and through 28 ...19989732530
bacterial croup caused by pasteurella haemolytica.we report a case of bacterial croup caused by pasteurella haemolytica. a nine-month-old girl was admitted to our hospital because of abrupt onset dyspnea and unconsciousness. from clinical and laboratory findings, she was diagnosed as having bacterial croup. pasteurella haemolytica was recovered from her tracheal secretion on admission. to our knowledge, this is the first report of bacterial croup caused by p. haemolytica.19989745781
duration of serum antibody responses following vaccination and revaccination of cattle with non-living commercial pasteurella haemolytica vaccines.this study was designed to determine the duration of serum antibody responses to pasteurella haemolytica whole cells (wc) and leukotoxin (lkt) in weanling beef cattle vaccinated with various non-living p. haemolytica vaccines. serum antibodies to p. haemolytica antigens were determined periodically through day 140 by enzyme-linked immunosorbent assays. at day 140, cattle were revaccinated, and antibody responses periodically determined through day 196. three vaccines were used in two experiments ...19989796051
genetic and immunologic analyses of plpe, a lipoprotein important in complement-mediated killing of pasteurella haemolytica serotype 1.pasteurella haemolytica serotype 1 is the bacterium most commonly associated with bovine shipping fever. the presence of antibodies against p. haemolytica outer membrane proteins (omps) correlates statistically with resistance to experimental p. haemolytica challenge in cattle. until now, specific p. haemolytica omps which elicit antibodies that function in host defense mechanisms have not been identified. in this study, we have cloned and sequenced the gene encoding one such protein, plpe. anal ...19989826333
target cell specificity of the pasteurella haemolytica leukotoxin is unaffected by the nature of the fatty-acyl group used to activate the toxin in vitro.the leukotoxin (lkta) of pasteurella haemolytica is active only against cells of ruminant origin. it is synthesised as an inactive protoxin encoded by the lkta gene and post-translationally modified to the active toxin by the product of the lktc gene. the lkta and lktc proteins were expressed separately in escherichia coli and partially purified. active lkta was produced in vitro in the presence of lktc and acyl-acyl carrier protein (acp) charged separately in vitro with a fatty-acyl group. the ...19989851045
[resistance of bovine and porcine pasteurella to florfenicol and other antibiotics].the resistance pattern of 221 (89 bovine, 132 porcine) pasteurella strains isolated in 1996 against 16 antibiotics or chemotherapeutics was determined by agar diffusion. pasteurella haemolytica showed a higher level of resistance compared to pasteurella multocida; porcine strains were more resistant than bovine strains. over 90% of porcine pasteurella multocida were sensible to penicillin g, ampicillin, cephalothin, polymyxin b, enrofloxacin, chloramphenicol and florfenicol. in addition, bovine ...19989880937
the pasteurella haemolytica 35 kda iron-regulated protein is an fbpa homologue.in a previous investigation, a 35 kda iron-regulated protein was identified from total cellular proteins of pasteurella haemolytica grown under iron-depleted conditions. this study reports identification of the gene (fbpa) encoding the 35 kda protein based on complementation of an enta escherichia coli strain transformed with a plasmid derived from a p. haemolytica lambda zap ii library. cross-reactivity was demonstrated between an anti-35 kda mab and a 35 kda protein expressed in this strain. f ...19989884235
cross-protection studies with three serotypes of pasteurella haemolytica in the goat model.cross-protection studies employing three serotypes of pasteurella haemolytica (ph) were performed in goats, with challenge exposure by transthoracic injection. indirect hemagglutination (iha) serum titers showed that the herd had been naturally infected with ph biovar a, serovar 2 (pha2) prior to the study. sixty-four weanling male spanish goats were randomly allotted to 16 groups. fifteen goats were given two transthoracic injections into the lungs 21 days apart with live pasteurella haemolytic ...19989504986
effect of pasteurella haemolytica outer membrane proteins on bovine neutrophils.the major outer membrane proteins (omps) isolated from pasteurella haemolytica induce alterations of the biological activity of bovine polymorphonuclear leukocytes (pmns). a dose-dependent reduction of the capacity of adherence to nylon wool in vitro was observed. omps also acted as chemotaxins at concentrations between 5 and 20 microg/ml. concentrations lower than 5 microg/ml did not give considerable results. preincubation with 5 microg/ml of omps led to modifications in the values of the phag ...19989514573
the presence of two low molecular mass proteins immunologically related to 14 kilodalton serum amyloid a in the lipoprotein fraction and their decreased serum concentrations in calves with experimentally induced pneumonia.a 14 kilodalton (kda) serum amyloid a (aposaa) protein was purified from cow serum. rabbit antiserum to the 14 kda aposaa recognized, in addition to the 14 kda protein, a 7.5-9.0 kda protein and a protein having a molecular mass of less than 6.5 kda (< 6.5 kda protein). the possibility that the two proteins were contaminants was excluded by results showing that the two proteins detected in early stages of purification procedures were not found in the purified 14 kda aposaa fraction, as revealed ...19989524941
pasteurella haemolytica ultraviolet-irradiated vaccine by parenteral and aerosol routes compared in the goat model.positive control 1 (pc1) (n = 9) goats were injected transthoracically into the left lung with live pasteurella haemolytica biovar a, serovar 1 (pha1) in polyacrylate (pa) beads on days 0 and 21. positive control 2 (pc2) (n = 6) goats were nebulized with live pha1 and pa beads on days 0 and 21. negative control (nc) goats (n = 6) were each injected transthoracically into the left lung with pa beads alone on days 0 and 21. four groups (n = 6) were administered pa beads mixed with ultraviolet (uv) ...19989662614
expression of the neutrophil chemoattractant interleukin-8 in the lesions of bovine pneumonic pasteurellosis.we investigated the expression of interleukin-8 (il-8) in pneumonic pasteurellosis of cattle because neutrophils are important mediators of tissue injury in this disease and because il-8 is a major neutrophil chemoattractant in other species. we also compared il-8 expression in bacterial and viral pneumonia, since the latter lacks the severe neutrophil exudation typical of pneumonic pasteurellosis. il-8 expression was assessed by northern analysis, in situ hybridization, enzyme-linked immunosorb ...19989539366
biotinylated proteins of pasteurella multocida and pasteurella haemolytica cause false-positive reactions with biotinylated probes in colony lift-hybridization assays. 19989514790
in vitro microbiological characterization of novel macrolide cp-163,505 for animal health specific use.a novel 16-membered-ring macrolide agent (cp-163,505, a reductive amination derivative of repromicin) was identified as an antibacterial against pasteurella haemolytica, p. multocida and actinobacillus pleuropneumoniae, important etiological agents of livestock respiratory disease. in vitro mic50/90 analysis revealed that cp-163,505 was more potent (4x) than tilmicosin against p. multocida, and equivalent to tilmicosin against p. haemolytica and a. pleuropneumoniae. in time kill kinetic studies, ...19989544934
induction of cd4+cd8+ double positive t cells and increase in cd5+ b cells in efferent lymph in sheep infected with trypanosoma evansi.the effects of trypanosoma evansi on efferent lymphocyte phenotypes draining from a lymph node primed with pasteurella haemolytica vaccine were studied in sheep. the prefemoral efferent lymphatic ducts of the infected sheep along with those of two uninfected sheep were surgically cannulated. lymph was collected and lymphocytes recovered from it analysed by two-colour indirect immunofluorescence staining and cytofluoremetry in a fluorescence activated cell analyser (facscan). the study showed the ...19989568615
cd34 molecule epitope distribution on cells of haematopoietic origin.the cd34 molecule belongs to the mucin membrane molecule family and is expressed on virtually all normal haematopoietic progenitor cells (hpc). due to its heavy glycosylation, several different epitopes exist on the molecule. based on the sensitivity of the glycosylated molecule to degradation with a glycoprotease from pasteurella haemolytica and neuraminidase, three classes of epitopes have been identified. the class i and ii epitopes are probably related to the glycosylated part of the molecul ...19989669673
rapid spread of a unique strain of pasteurella haemolytica serotype 1 among transported calves.to determine the rate and mode of infectious spread of pasteurella haemolytica among calves maintained under typical conditions during collection, transport, and the first month of feeding.19989563620
biovariants of isolates of pasteurella from domestic and wild ruminants.a total of 608 bacterial isolates previously identified as pasteurella haemolytica biotypes a and 3, p. trehalosi, and p. multocida, were separated into 73 distinct biovariants using 21 phenotypic characteristics. the largest group (54%) of wildlife isolates was identified as biogroup 2 and biogroup 2 variants. biogroup 2 and biogroup 2 variants accounted for only 17% of isolates from domestic ruminants and were all from sheep. in contrast, 43% of isolates from domestic ruminants were identified ...19989526860
pasteurella haemolytica leukotoxin-induced increase in phospholipase a2 activity in bovine neutrophils.exposure of bovine neutrophils to pasteurella haemolytica leukotoxin (lkt) stimulates the production of leukotriene b4 (ltb4), which is believed to be an important chemotactic agent in the development of acute fibrinopurulent pneumonic infection in cattle. the involvement of phospholipase a2 (pla2) in lkt-induced synthesis of ltb4 was studied by using bovine neutrophils labeled with 3h-arachidonate ([3h]aa). incubation of isolated neutrophils with [3h]aa resulted in incorporation of radioactivit ...19989573065
evaluation of a computerized antimicrobial susceptibility system with bacteria isolated from animals.the biomic is a computerized system used to calculate the minimal inhibitory concentration (mic) of an antimicrobial agent from a zone of inhibition generated by a disk diffusion test. this system was developed using bacterial pathogens of human origin. this study investigated the use of the biomic system for determining mics for bacterial pathogens from animals. the mics generated by the biomic system were compared with the mics generated using a broth microdilution testing method. a total of 6 ...19989576344
evaluation of a multivalent pasteurella haemolytica vaccine in bighorn sheep: protection from experimental challenge.the efficacy of a multivalent pasteurella haemolytica vaccine (a1, a2, t10) in reducing morbidity and mortality associated with pneumonic pasteurellosis in bighorn sheep (ovis canadensis) was examined. fifteen captive bighorns were divided equally into three treatment groups based on vaccination status: control (no vaccination), one dose 10 days prior to challenge, or one or two doses 57 wk prior to challenge. at challenge, each bighorn received about 6.2 x 10(7) colony forming units of p. haemo ...19989577780
role of sialosyl lewis(a) in adhesion of colon cancer cells--the antisense rna approach.to study whether the adhesion of colon cancer cells to e-selectin can be directly affected by changes in the expression level of sialosyl le(a) antigen we created a specific loss-of-function phenotype. a stable subclone (cx-1.1) with high expression of sialosyl le(a) structure, obtained from a heterogenous population of colon carcinoma cx-1 cells, was transfected with an expression vector containing a fragment of cdna for alpha1,3/4-fucosyltransferase in antisense orientation. after transfection ...19989578490
in vivo effect of pasteurella haemolytica infection on bovine neutrophil morphology.to determine whether characteristic changes in neutrophil morphology caused in vitro by pasteurella haemolytica leukotoxin (lkt) can be observed in vivo by electron microscopic examination of infected tissue chamber fluids and pneumonic lungs.19989582961
characterization of a 54-kda heat-shock-inducible protein of pasteurella haemolytica.growth-condition-dependent antigens play a role in the virulence or protective capacity of many organisms. enhanced production of an approximately 54-kda protein was detected in heat-shocked cultures of pasteurella haemolytica. the heat-shock-inducible protein cross-reacted with antibodies to 60-kda heat-shock proteins of mycobacterium tuberculosis, chlamydia, and escherichia coli groel. a probe containing the e. coli groel operon hybridized with fragments of p. haemolytica chromosomal dna on so ...19989595628
anti-inflammatory benefits of tilmicosin in calves with pasteurella haemolytica-infected lungs.to determine whether tilmicosin alters neutrophil infiltration or function, induces neutrophil apoptosis, and affects accumulation of leukotriene b4 (ltb4) or tumor necrosis factor-alpha (tnf-alpha) in lungs of calves experimentally infected with pasteurella haemolytica.19989622749
efficacy of intranasal administration of formalin-killed pasteurella haemolytica a2 against intratracheal challenge in goats.a trial was conducted to compare the efficacy of intranasal vaccination in protecting goats against pneumonic pasteurellosis with intramuscular vaccination using an oil adjuvant vaccine, and a combination of the two methods. forty goats were divided into four equal groups. group 1 was vaccinated twice intranasally with formalin-killed pasteurella haemolytica a2, group 2 was vaccinated twice intramuscularly with an oil adjuvant vaccine containing p haemolytica a7, and group 3 was initially vaccin ...19989595632
pasteurella haemolytica a1-derived leukotoxin and endotoxin induce intracellular calcium elevation in bovine alveolar macrophages by different signaling pathways.leukotoxin and endotoxin derived from pasteurella haemolytica serotype 1 are the primary virulence factors contributing to the pathogenesis of lung injury in bovine pneumonic pasteurellosis. activation of bovine alveolar macrophages with endotoxin or leukotoxin results in the induction of cytokine gene expression, with different kinetics (h. s. yoo, s. k. maheswaran, g. lin, e. l. townsend, and t. r. ames, infect. immun. 63:381-388, 1995; h. s. yoo, b. s. rajagopal, s. k. maheswaran, and t. r. a ...19989596757
membrane protein proteolysis assayed by fluorescence quenching: assay of o-sialoglycoprotein endopeptidase.the assay of the o-sialoglycoprotein endopeptidase of pasteurella haemolytica has previously used the cleavage of 125i-labeled glycophorin a, measured by sds-page, autoradiography, gel-slicing, and scintillation counting. a new assay is based on the increased fluorescence which results from proteolytic cleavage of a fluorescence-quenched micellar substrate, 4,4-difluor-5,7-dimethyl-4-bora-3 alpha, 4 alpha-diaza-s-indacene-3-propionic acid conjugated to glycophorin a (bodipy-fl-glycophorin a). mi ...19989606137
stimulation of the bronchus-associated lymphoid tissue of goats and its effect on in vitro colonization by pasteurella haemolytica.twenty goats of about 7 months of age were divided into five groups. the goats in groups 1 and 2 were exposed once, using an intranasal spray to 2 ml of an inoculum containing 10(6) colony-forming units/ml of living or dead pasteurella haemolytica a2, respectively. the goats in groups 3 and 4 were similarly exposed twice at a 2-week interval. group 5 was the untreated control. the number and size of the bronchus-associated lymphoid tissue (balt) in goats exposed twice to either living or dead or ...19989618886
bovine platelet adhesion is enhanced by leukotoxin and sialoglycoprotease isolated from pasteurella haemolytica a1 cultures.platelet and fibrin deposits are among characteristic changes observed in lung alveoli of cattle with pasteurellosis induced by pasteurella haemolytica (biotype a, serotype 1). to determine whether the platelet function could be directly affected by protein products produced by the bacterium, the effects of leukotoxin and o-sialoglycoprotease, culture supernatant antigen secreted by pasteurella haemolytica a1, on bovine platelet activation were examined by evaluating the enhancement of platelet ...19989646468
the carriage of pasteurella haemolytica in sheep and its transfer between ewes and lambs in relation to mastitis.the possible presence of pasteurella haemolytica in the mouth of lambs and on the skin of the teats of ewes was investigated. the organism was found in the mouth of ewes and lambs and, soon after lambing, on the teat skin of ewes. it was not isolated from the teat skin of pregnant ewes 1-14 days before lambing or from the teat skin one week after the lambs had been weaned. the transfer of p. haemolytica to the teat skin is undoubtedly mediated by the lamb. there is ample opportunity for the teat ...19989651812
high-performance liquid chromatography of pasteurella haemolytica leukotoxin using anion-exchange perfusion columns.an exotoxin, called leukotoxin (lkt), from pasteurella haemolytica, which had previously proved difficult to purify, was purified by high-performance liquid chromatography using rigid highly hydrophilic microparticulate anion-exchange columns. these anion-exchange stationary phases were employed to overcome difficulties of the relatively hydrophobic lkt interacting with dextran or styrene-based resins. while a short non-porous deae column allowed the partial microscale purification of the leukot ...19989652117
increase in cd5+ b cells and depression of immune responses in sheep infected with trypanosoma evansi.the effects of trypanosoma evansi on the cellular and humoral immune responses of sheep to pasteurella haemolytica vaccine were studied. peripheral blood lymphocytes (pbls) from the sheep were analysed using single and double-colour indirect immunofluorescence staining and flow cytometry to monitor changes in circulating b and t cell subsets. serum antibody responses were assayed using the enzyme-linked immunosorbent assay technique (elisa), in addition to measuring local skin reactions at the s ...19989656456
antibody responses to pasteurella haemolytica 1:a and three of its outer membrane proteins in serum, nasal secretions, and bronchoalveolar lavage fluid from calves.to determine systemic and mucosal antibody responses in calves to pasteurella haemolytica 1:a and to 2 major outer membrane proteins (omp) and 1 major iron-regulated omp of p haemolytica 1:a.19989622742
serum-free culture of pasteurella haemolytica optimized for leukotoxin production.to screen supernatants of pasteurella haemolytica cultures grown in 4 serum-free culture media for maximal leukotoxin (lkt) production and minimal protein concentration as an optimal source of lkt for purification.19989659550
comparison of serologic and protective responses induced by two pasteurella vaccines.vaccine development for the prevention of pneumonic pasteurellosis remains a critical issue for the feedlot industry. most currently available pasteurella vaccines are formulated to stimulate immunity by either providing an adequate antigenic mass in the administered dose, or by relying on subsequent production of antigens by in vivo growth of live organisms. the ability of these different types of vaccines to stimulate rapid and high titres to key antigens is a key factor that will influence su ...19989684046
isolation of a nicotinamide-adenine dinucleotide (nad)-dependent pasteurella haemolytica-like organism from the placenta of an aborted cow. 19989711392
pasteurella haemolytica complicated respiratory infections in sheep and goats.respiratory infections which commonly occur in sheep and goats often result from adverse physical and physiological stress combined with viral and bacterial infections. inevitably, pasteurella haemolytica pneumonia occurs as a result of these interactions. in this review, we present recent advances in research on the complex etiology of pneumonia involving p. haemolytica. initially stress, induced by factors such as heat, overcrowding, exposure to inclement weather, poor ventilation, handling an ...19989689740
characterization of a fourth lipoprotein from pasteurella haemolytica a1 and its homology to the ompa family of outer membrane proteins.a fourth lipoprotein gene from pasteurella haemolytica a1 was cloned and characterized. the plpd gene encodes a 31-kda lipoprotein (plp4) which could be recognized in western immunoblot by sera from calves immunized with the culture supernatant vaccine presponse. this suggests that plp4 is one of the immunogenic molecules in the p. haemolytica a1 culture supernatant. the lipoprotein nature of plp4 was confirmed by labelling with [3h]palmitate and inhibition of leader peptide cleavage with globom ...19989711841
occurrence of some viruses and bacteria involved in respiratory diseases of ruminants in hungary.serological surveys, virological and bacteriological investigations were carried out on large populations of lambs and calves kept in intensive fattening units on hungarian large-scale farms, in order to study the occurrence of viruses and bacteria involved in the respiratory disease complex. the investigations were carried out in stocks where 5-20% of the young animals succumbed to acute or chronic pneumonia every year. serological surveys revealed that seropositivity to bovine adenovirus type ...19989713141
proliferative responses of peripheral blood leucocytes of sheep infected with trypanosoma evansi.the effects of trypanosoma evansi on the proliferative responses of ovine peripheral blood leucocytes (pbl) were examined in in vitro cell culture systems. sheep were vaccinated against pneumonic pasteurellosis with a monovalent pasteurella haemolytica vaccine and then infected with t. evansi treu 2143. from 1 week post-infection (p.i.), the pbl were separated and stimulated in cultures with either concanavalin a (con a), bacterial lipopolysaccharide (lps), pasteurella antigen (p.ag), or homolog ...19989716108
occurrence of autoantibodies to cilia in lambs with a 'coughing syndrome'.a respiratory disease of lambs that has been termed the 'coughing syndrome' has been observed in the mid-western region of the united states of america. mycoplasma ovipneumoniae (m. ovipneumoniae) and mycoplasma arginini (m. arginini) were routinely isolated from the respiratory tract of lambs with this disease. a high level of antibodies reactive with ovine cilia of the upper respiratory tract was detected in the sera from many of the lambs in affected flocks but not in sera of lambs from unaff ...19989730216
pneumonic pasteurellosis associated with pasteurella hemolytica serotype a6 in american bison (bison bison). 19989786525
the biphasic mrna expression pattern of bovine interleukin-8 in pasteurella haemolytica lipopolysaccharide-stimulated alveolar macrophages is primarily due to tumor necrosis factor alpha.pasteurella haemolytica serotype 1 is the bacterial agent responsible for the pathophysiological events associated with bovine pneumonic pasteurellosis. our previous studies support a role for the lipopolysaccharide (lps) from p. haemolytica in the induction of proinflammatory cytokines. one of the pathological hallmarks of bovine pneumonic pasteurellosis is an influx of neutrophils into the alveolar spaces. this pronounced influx suggests the local production of a chemotactic factor(s) such as ...19989712752
the clinical efficacy of enrofloxacin in the treatment of experimental bovine pneumonic pasteurellosis.the clinical efficacy of enrofloxacin was tested in calves with experimentally induced pneumonic pasteurellosis. a strain of pasteurella haemolytica, biotype a, serotype 1 (p. haemolytica a1), which had been isolated from an outbreak of pneumonic pasteurellosis in feedlot calves, was used to induce the disease in 24 eight-month-old calves. each animal received, by intratracheal injection, 6 x 10(11) colony forming units of p. haemolytica a1 in a four-hour log phase culture. twelve similar animal ...19989741054
characterization of a pasteurella haemolytica a1 mutant deficient in production of three membrane lipoproteins.to determine whether a pasteurella haemolytica a1 mutant that is unable to produce membrane lipoproteins has reduced susceptibility to complement-mediated killing, and to characterize the mutant strain.19989781461
serologic responses of young colostrum fed dairy calves to antigens of pasteurella haemolytica a1.the potential and limitations of early calfhood vaccination to induce active immunity to pasteurella haemolytica a1 in conventional colostrum fed calves were investigated. holstein dairy calves (n = 29) were vaccinated at 2 and 4 weeks of age, or at 6 and 8 weeks of age with a commercial culture supernatant vaccine (presponse, langford inc., guelph, ont., canada), or remained unvaccinated as controls. serum antibody titres were measured using an indirect bacterial agglutination assay, a leukotox ...19989796059
the association of titers to haemophilus somnus, and other putative pathogens, with the occurrence of bovine respiratory disease and weight gain in feedlot calves.serum samples were obtained from 602 calves (from 19 groups in four feedlots: three in ontario, and one in alberta) upon arrival at the feedlot and 28 d later. of these calves, 202 developed bovine respiratory disease (brd) and 400 did not develop brd. based on high antibody titers noted upon arrival, we infer that most calves were exposed to haemophilus somnus prior to arrival at the feedlot. within a group, calves with high titers on arrival had a reduced risk of developing brd later. most cal ...19989798091
discrimination between apo and iron-loaded forms of transferrin by transferrin binding protein b and its n-terminal subfragment.many pathogens of the pasteurellaceae and neisseriaceae possess a surface receptor that binds transferrin (tf) as an initial step in an iron acquisition process. this receptor is comprised of two proteins, transferrin binding protein a (tbpa) and transferrin binding protein b (tbpb). since the ability to recognize the iron-loaded form of tf preferentially would be a useful attribute of these receptors, we examined this property in a number of bacterial species. in solid-phase binding assays with ...19989817820
pulmonary venous thrombosis in caprine pasteurella pneumonia.a 3-year-old angora goat that developed acute fibrinous pleuropneumonia associated with pasteurella haemolytica infection had thrombotic occlusion of a large pulmonary vein. thrombosis of pulmonary capillaries occurs in pneumonic pasteurellosis, but large vessels are not commonly affected. this unusual lesion may reflect the procoagulant effect of pasteurella endotoxin on vascular endothelium. an incidental observation was the presence of myocardial-type muscle fibres in the tunica media of the ...19979179755
purification and partial characterization of the ompa family of proteins of pasteurella haemolytica.this study was conducted to partially characterize and identify the purity of two major outer membrane proteins (omps) (with molecular weights of 32,000 and 35,000 [32k and 35k, respectively]) of pasteurella haemolytica. the 35k and 32k major omps, designated pasteurella outer membrane proteins a and b (poma and pomb, respectively), were extracted from p. haemolytica by solubilization in n-octyl polyoxyl ethylene. the p. haemolytica strain used was a mutant serotype a1 from which the genes expre ...19978975914
increase of glycocalyx and altered lectin agglutination profiles of pasteurella haemolytica a1 after incubation in bovine subcutaneous tissue chambers in vivo or in ruminant serum in vitro.pasteurella haemolytica serotype a1 (bovine strain ok) was incubated for 2 and 6 h in bovine subcutaneous tissue chambers in vivo, and ovine strain 82-25 and bovine strain l011 were incubated in vitro for 2 h in heat-inactivated ovine or bovine serum from which gamma globulin had been depleted by protein g affinity chromatography to assess changes in morphology and lectin agglutination profiles (strains 82-25 and l101 only). cells, removed from chambers after 2 h, were covered with an extensive, ...19979038303
Refresh
firstprev
12345678910...
nextlast
Displaying items 701 - 800 of 1767