| bacterial identity and characteristics in healthy and unhealthy respiratory tracts of sheep and calves. | the aim of this study was to compare different bacteriological aspects of the respiratory systems of healthy (h) versus unhealthy (uh) animals with respiratory signs. the prevalence of different bacterial species was determined in the upper and lower respiratory tract of h and uh najdi sheep, somali sheep and holstein calves. the characteristics of pasteurella spp. isolates, and the biotype of pasteurella haemolytica were identified in h and uh animals, eighteen out of 28 (64.3%) of the identifi ... | 1997 | 9266661 |
| aspects of the pharmacokinetics of doxycycline given to healthy and pneumonic east african dwarf goats by intramuscular injection. | the effect of experimentally induced pasteurella haemolytica pneumonia on the pharmacokinetics of doxycycline (doxycen retard) administered intramuscularly was studied in seven east african dwarf goats. the study was conducted in two consecutive phases, separated by a washout period of four weeks. the experimental infection, induced by intratracheal administration of 5 ml of 10(7) to 10(9) cfu/ml of pasteurella haemolytica, produced a temperature rise, depression and laboured breathing within 6- ... | 1997 | 9266665 |
| computer-based analyses of the protein constituents of transport systems catalysing export of complex carbohydrates in bacteria. | bacteria synthesize and secrete an array of complex carbohydrates including exopolysaccharides (epss), capsular polysaccharides (cpss), lipopolysaccharides (lpss), lipo-oligosaccharides (loss) and teichoic acids (tcas). we have analysed the families of homologous proteins that appear to mediate excretion of complex carbohydrates into or across the bacterial cell envelope. two principal families of cytoplasmic-membrane transport systems appear to drive polysaccharide export: polysaccharide-specif ... | 1997 | 9274022 |
| evolutionary genetics of pasteurella haemolytica isolates recovered from cattle and sheep. | genetic diversity and relationships among 194 pasteurella haemolytica isolates, which were recovered predominantly from cattle (39%) and sheep (58%) suffering from pneumonic pasteurellosis in the united kingdom, germany, and the united states, were estimated by examination of allelic variation at 18 enzyme-encoding loci detected by multilocus enzyme electrophoresis. the isolates formed two major divisions. one included 178 pasteurella haemolytica sensu stricto strains representing serotypes a1, ... | 1997 | 9284123 |
| binding of pasteurella haemolytica leukotoxin to bovine leukocytes. | pasteurella haemolytica is the principal bacterial pathogen in the bovine respiratory disease complex. this organism produces an exotoxin (referred to as leukotoxin) during logarithmic-phase growth that is a potent leukocyte-modulating agent. at low concentrations, it activates neutrophils and mononuclear phagocytes to release inflammatory mediators, while at the same time making these cells destined to undergo apoptotic cell death. at higher concentrations, the toxin causes rapid swelling and l ... | 1997 | 9284143 |
| a putative leucine zipper activator of pasteurella haemolytica leukotoxin transcription and the potential for modulation of its synthesis by slipped-strand mispairing. | a pasteurella haemolytica cosmid clone that activates leukotoxin transcription in escherichia coli has been isolated. the activator locus, alxa, is part of a continuous open reading frame that includes the type i hsdm methylase gene. alxa and hsdm peptides are processed from a precursor, and translation of the polyprotein can be modulated by slipped-strand mispairing across a pentanucleotide repeat, acagc, within the 5' end of alxa-hsdm. extracts containing alxa can bind to a leukotoxin promoter ... | 1997 | 9284183 |
| efficacy of doxycycline in a goat model of pasteurella pneumonia. | the clinical efficacy of doxycycline (doxycen, cenavisa, spain), a long-acting preparation, was evaluated for treatment of pasteurella haemolytica infection in 6 goats. one goat was not infected and served as a control. the disease was induced by intratracheal inoculation of 10(7) to 10(9) cfu of p. haemolytica. confirmation of respiratory disease was based on evidence of appropriate clinical signs. before and after initiation of doxycycline treatment on day 10, each goat was examined daily. thr ... | 1997 | 9291074 |
| serum antibody responses of cattle vaccinated with partially purified native pasteurella haemolytica leukotoxin. | the objective of these experiments was to study the serum antibody responses of cattle to partially purified, native pasteurella haemolytica a1 leukotoxin (lkt) formulated with a commercial aluminum hydroxide-dda-bromide adjuvant. in two experiments, calves received two intramuscular injections 21 days apart and sera were obtained periodically. serum antibody responses to p. haemolytica outer membrane proteins (omps), formalinized p. haemolytica, and lkt were determined. in experiment a, holstei ... | 1997 | 9302755 |
| refolding of recombinant pasteurella haemolytica a1 glycoprotease expressed in an escherichia coli thioredoxin gene fusion system. | pasteurella haemolytica a1 secretes an o-sialoglycoprotein endopeptidase (ec. 3.4.24.57) (glycoprotease: gcp) which is specific for o-linked sialoglycoproteins. when the cloned gene is expressed in escherichia coli, the recombinant glycoprotease (rgcp) is secreted to the periplasm where it is present as a disulfide-linked aggregate which lacks enzymatic activity. in vitro refolding and activation of rgcp by mammalian protein disulfide isomerase (pdi) or by the e. coli chaperones (dnak, dnaj and ... | 1997 | 9314606 |
| nasal carriage of pasteurella haemolytica serotypes by sheep and goats in jordan. | | 1997 | 9316235 |
| isolation of pasteurella haemolytica from grass, drinking water, and straw bedding used by sheep. | pasteurella haemolytica was isolated from three of 18 grass samples and four of 18 water samples collected from two grazing fields occupied by sheep. this microorganism was also isolated from three of nine straw bedding samples collected from a pen housing ewes affected by mastitis caused by p. haemolytica. the same ewes developed scabbed papilloma-like lesions on the teat and udder skin. these lesions were colonized by p. haemolytica of various serotypes. colder, wetter weather seems to prolong ... | 1997 | 9321460 |
| influence of immunization on the pulmonary inflammatory response of rabbits induced by pasteurella haemolytica a1 lipopolysaccharide. | immune complex formation has long been thought to play a role in the pathogenesis of pasteurella haemolytica pneumonia. this study in laboratory rabbits was designed to investigate immune-mediated damage in respiratory tissue caused by lipopolysaccharide (lps). severe lesions were induced by the intratracheal (it) injection of p. haemolytica a1 lps (50 micrograms) into rabbits previously immunized with p. haemolytica killed whole cells emulsified with freund's incomplete adjuvant (fia); these le ... | 1997 | 9352438 |
| susceptibility of dall sheep (ovis dalli dalli) to pneumonia caused by pasteurella haemolytica. | we evaluated susceptibility of dall sheep (ovis dalli dalli) to bacterial pneumonia induced by two strains of pasteurella haemolytica of domestic sheep origin by evaluating the sensitivity of blood neutrophils of eight dall sheep to lysis by cytotoxins of p. haemolytica, and by intratracheal inoculation of three dall sheep, two bighorn sheep (ovis canadensis), and two domestic sheep with 3.7 x 10(6) or 2.5 x 10(7) colony forming units of p. haemolytica. neutrophils from the dall sheep were more ... | 1996 | 9359056 |
| experimental contact of bighorn sheep (ovis canadensis) with horses and cattle, and comparison of neutrophil sensitivity to pasteurella haemolytica cytotoxins. | peripheral blood neutrophils from horses, cattle, and rocky mountain bighorn sheep (ovis canadensis canadensis) were evaluated for susceptibility to cytotoxin-dependent lysis of different biotypes and serotypes of pasteurella haemolytica of domestic sheep, cattle, bighorn sheep, or mountain goat (oreamnos americana) origin utilizing a cytotoxicity assay which measures the degree of bacteria cytotoxin-killing of neutrophils. all isolates of p. haemolytica (biotypes a and t) were noncytotoxic to h ... | 1996 | 9359057 |
| further studies of the relationships among strains classified as taxon 15, taxon 18, taxon 20, (pasteurella) granulomatis or the (pasteurella) haemolytica-complex in ruminants using quantitative evaluation of phenotypic data. | ninety-three trehalose-negative (p.) haemolytica-like strains of ruminant, porcine and leprine origin were investigated. a quantitative evaluation of phenotypic tests was used and the results obtained were compared with those from 246 previously investigated ruminant strains. cluster analysis of the results obtained displayed most of the taxa as distinct groups which could be related to differences in key characters. although only minor phenotypic differences were observed between the taxa inves ... | 1997 | 9361379 |
| genotypic relationships among strains classified under the (pasteurella) haemolytica-complex as indicated by ribotyping and multilocus enzyme electrophoresis. | two-hundred and one strains classified under the (pasteurella) haemolytica-complex isolated from cattle, sheep, deer, pigs, hares and rabbits were investigated by ribotyping. fifty-nine of these strains were selected for further studies using multilocus enzyme electrophoresis (mee). a correlation between the clusters identified by ribotyping and mee was demonstrated and the results furthermore indicated that a genetic basis exists for most clusters previously outlined by the use of quantitative ... | 1997 | 9361380 |
| effects of pasteurella haemolytica leukotoxin and lipopolysaccharide on histamine, prostanoid, and leukotriene release by bovine lung parenchyma in vitro. | to identify the effect of pasteurella haemolytica lipopolysaccharide (lps) and leukotoxin (lkt) on spontaneous and calcium ionophore-induced histamine and inflammatory mediator release from isolated bovine lung parenchyma. | 1997 | 9361883 |
| bovine respiratory tract disease caused by bovine viral diarrhea virus. | although several viruses and bacteria are capable of inducing bovine respiratory tract disease, a pivotal organism in the cause of this complex disease may be bovine viral diarrhea virus (bvdv). circumstantial evidence has long supported this hypothesis. it is frequently present in diseased respiratory tract tissues often together with other viruses or bacteria. field observations suggest marked synergism occurs. researchers have confirmed that, in most instances, the virus itself elicits only a ... | 1997 | 9368990 |
| bacterial pneumonia. | bacteria play a critical role in the severe pneumonia and fatalities associated with the bovine respiratory disease complex. although numerous bacteria have the potential to cause pneumonia, only a small number of these are responsible for the majority of cases of disease. virulence and immunogenic characteristics of these organisms are important determinants of the host response to infection. these bacterial characteristics are reviewed and applied to a discussion of the epidemiology, pathogene ... | 1997 | 9368991 |
| bacterial ghosts as multifunctional vaccine particles. | expression of cloned phix174 gene e in gram-negative bacteria results in lysis of the bacteria by formation of an e-specific transmembrane tunnel structure built through the cell envelope complex. bacterial ghosts have been produced from a variety of bacteria including escherichia coli. salmonella typhimurium, salmonella enteritidis, vibrio cholerae, klebsiella pneumoniae, actinobacillus pleuropneumoniae, haemophilus influenzae, pasteurella haemolytica, pasteurella multocida, and helicobacter py ... | 1997 | 9382740 |
| evaluation of a multivalent pasteurella haemolytica vaccine in bighorn sheep: safety and serologic responses. | we examined effects of a multivalent pasteurella haemolytica vaccine (serotypes a1, a2, t10) on humoral immune responses and p. haemolytica isolation rates in bighorn sheep (ovis canadensis). thirty captive bighorns, divided into groups of three on the basis of age, sex, and previous history of pneumonic pasteurellosis, received 0, 1, or 2 vaccine doses. mild, transient lameness in most bighorns 1 day after initial vaccination was the only adverse effect observed. oropharyngeal (> or = 75%) and ... | 1997 | 9391957 |
| characterization of the pasteurella haemolytica transferrin receptor genes and the recombinant receptor proteins. | the tbpa and tbpb genes encoding the transferrin receptor proteins, tbpa and tbpb, from pasteurella haemolytica a1 were cloned, sequenced and expressed in escherichia coli. the genes were organized in a putative operon arrangement of tbpb- tbpa. the tbpb gene was preceded by putative promoter and regulatory sequences, and followed by a 96 base pair intergenic sequence in which no promoter regions were found, suggesting that the two genes are coordinately transcribed. the deduced amino acid seque ... | 1997 | 9405205 |
| purification and characterization of a 31-kilodalton iron-regulated periplasmic protein from pasteurella haemolytica a1. | a prominent iron-regulated periplasmic protein was purified from pasteurella haemolytica grown in an iron-deficient chemically defined medium. the protein was purified by anion exchange chromatography and appeared as a single band by sds-page with a molecular weight of 32,000. a yield of five mg was obtained from 91 mg of protein extract. the iron-regulated protein existed as a monomer in the native state with an average molecular weight of 29,877 as determined by analytical ultracentrifugation. ... | 1997 | 9413558 |
| 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 ... | 1998 | 9442932 |
| 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 ... | 1998 | 9466945 |
| the humoral immune response in cattle after immunization with a multivalent ibr/pi3/pasteurella haemolytica a1 leukotoxin vaccine. | a multivalent vaccine consisting of inactivated bovine herpes virus-1 (bhv-1), also known as infectious bovine rhinotracheitis virus (ibr), para-influenza type-3 virus (pi3) and the leukotoxin of pasteurella haemolytica a1, were combined with the addition of aluminium hydroxide as adjuvant, and administered to post-weaned calves, and the serum tested for seroconversion to each antigen. two groups of calves (n = 150 and n = 68) were used and were randomly divided into three subgroups. the first g ... | 1997 | 9467176 |
| the leukocyte common antigen (cd45) on human pre-b leukemia cells: variant glycoprotein form expression during the cell exposure to phorbol ester is blocked by a nonselective protein kinase inhibitor h7. | the human pre-b acute lymphoblastic leukemia cell line reh6 was utilized for characterization of cd45 glycoprotein by monoclonal antibodies (mab) recognizing four distinct cd45 antigen specificities, i.e. nonrestricted cd45, restricted cd45ra, cd45rb and cd45r0. immunoprecipitation revealed two antigen specificities on reh6 cells of m.w. 220 kda and 190 kda, both presenting wide range of isoelectric point pi approximately 6.0-7.5. nonrestricted cd45 epitopes were not affected by the sialyl acid ... | 1997 | 9473774 |
| 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 ... | 1998 | 9504986 |
| 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 ... | 1998 | 9514573 |
| biotinylated proteins of pasteurella multocida and pasteurella haemolytica cause false-positive reactions with biotinylated probes in colony lift-hybridization assays. | | 1998 | 9514790 |
| 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 ... | 1998 | 9524941 |
| 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 ... | 1998 | 9526860 |
| 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 ... | 1998 | 9539366 |
| 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. | 1998 | 9540872 |
| 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, ... | 1998 | 9544934 |
| 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. | 1998 | 9563620 |
| 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. | 1998 | 9563625 |
| 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 ... | 1998 | 9568615 |
| 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 ... | 1998 | 9573065 |
| 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 ... | 1998 | 9573513 |
| 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 ... | 1998 | 9576344 |
| 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 ... | 1998 | 9577780 |
| 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 ... | 1998 | 9578490 |
| 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. | 1998 | 9582961 |
| 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 ... | 1998 | 9595628 |
| 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 ... | 1998 | 9595632 |
| 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 ... | 1998 | 9596757 |
| 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 ... | 1998 | 9606137 |
| 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 ... | 1998 | 9618886 |
| 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. | 1998 | 9622742 |
| 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. | 1998 | 9622749 |
| 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 ... | 1998 | 9646468 |
| 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 ... | 1998 | 9651812 |
| 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 ... | 1998 | 9652117 |
| 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 ... | 1998 | 9656456 |
| 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. | 1998 | 9659550 |
| 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) ... | 1998 | 9662614 |
| 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 ... | 1998 | 9669673 |
| 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 ... | 1998 | 9684046 |
| 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 ... | 1998 | 9689740 |
| isolation of a nicotinamide-adenine dinucleotide (nad)-dependent pasteurella haemolytica-like organism from the placenta of an aborted cow. | | 1998 | 9711392 |
| 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 ... | 1998 | 9711841 |
| 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 ... | 1998 | 9712752 |
| 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 ... | 1998 | 9713141 |
| 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 ... | 1998 | 9716108 |
| 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 ... | 1998 | 9730216 |
| 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 ... | 1998 | 9732530 |
| 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 ... | 1998 | 9741054 |
| 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. | 1998 | 9745781 |
| 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. | 1998 | 9781461 |
| pneumonic pasteurellosis associated with pasteurella hemolytica serotype a6 in american bison (bison bison). | | 1998 | 9786525 |
| 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 ... | 1998 | 9796051 |
| 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 ... | 1998 | 9796059 |
| 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 ... | 1998 | 9798091 |
| 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 ... | 1998 | 9817820 |
| 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 ... | 1998 | 9826333 |
| 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 ... | 1998 | 9851045 |
| [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 ... | 1998 | 9880937 |
| 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 ... | 1998 | 9884235 |
| pulsed-field gel electrophoresis is more efficient than ribotyping and random amplified polymorphic dna analysis in discrimination of pasteurella haemolytica strains. | one hundred thirty-three strains of pasteurella haemolytica of both biotypes (90 and 43 strains of biotypes a and t, respectively) and almost all the serotypes were subjected to ribotyping, random amplified polymorphic dna (rapd) analysis, and pulsed-field gel electrophoresis (pfge) analysis for epidemiological purposes. a total of 15 patterns recorded as ribotypes ha to ho were found for the p. haemolytica biotype a strains, with ribotypes ha, hc, and hd being encountered most often (66 strains ... | 1999 | 9889223 |
| 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 ... | 1998 | 9895270 |
| induction of cd18-mediated passage of neutrophils by pasteurella haemolytica in pulmonary bronchi and bronchioles. | pasteurella haemolytica is an important respiratory pathogen of cattle that incites extensive infiltrates of neutrophils into the lung. in addition to the parenchymal damage caused by factors released by p. haemolytica, neutrophils contribute to the pathologic changes in the lungs. molecules which mediate neutrophil infiltration into the lungs during p. haemolytica pneumonia are poorly characterized. to determine whether the cd18 family (beta2-integrin) of leukocyte adhesion molecules mediates i ... | 1999 | 9916073 |
| mast cells of the bovine trachea: staining characteristics, dispersion techniques and response to secretagogues. | sections of the lower trachea of cattle, fixed in either carnoy's or formalin, were stained with toluidine blue, alcian blue, or alcian blue and safranin o to study the mast cell population. after toluidine blue staining, about twice as many cells in tissue fixed in carnoy's contained dark blue granules compared with tissue fixed in formalin. in addition, for the first time in cattle, a population of cells containing red granules was identified after staining with alcian blue and safranin o. mos ... | 1999 | 9918327 |
| 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 ... | 1999 | 9919366 |
| 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, ... | 1998 | 9987187 |
| 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 ... | 1999 | 10028248 |
| 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 ... | 1999 | 10037813 |
| 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 ... | 1998 | 10052589 |
| actin polymerization enhances pasteurella haemolytica leukotoxicity. | pasteurella haemolytica leukotoxin is cytotoxic to bovine leukocytes, causing increased cell membrane permeability, osmotic swelling, release of cytosolic proteins and cell lysis. these studies were designed to test if leukotoxin causes release of the cytoskeletal protein, actin, from bovine leukemia cells and if purified actin-influenced bacterial growth or leukotoxin production. culture supernatants caused a 7-fold decrease in viability of bovine leukemia cells and increased cell permeability ... | 1999 | 10063536 |
| primary and anamnestic responses of bovine bronchoalveolar and peripheral blood lymphocyte subsets to aerosolized pasteurella haemolytica a1. | site-specific responses of bronchoalveolar and peripheral blood lymphocyte subsets were compared during primary and anamnestic immune responses against live pasteurella haemolytica a1 (ph1). eight 1-year old calves were sequentially exposed intrabronchially with aerosolized ph1 on days 0, 14, and 21, and two calves were sham exposed. bronchoalveolar and peripheral blood lymphocytes were analyzed before each ph1 exposure, and on days 3 and 7 post exposure using single and two-color flow cytometry ... | 1999 | 10077422 |
| pasteurella haemolytica leukotoxin induced apoptosis of bovine lymphocytes involves dna fragmentation. | it has been reported that pasteurella haemolytica leukotoxin (lkt) induces morphologic changes in bovine leukocytes consistent with apoptosis in vitro, but dna fragmentation was not observed. we investigated whether bovine lymphocytes undergo dna fragmentation during lkt-induced apoptosis. bovine peripheral blood lymphocytes were isolated by density gradient centrifugation and exposed to lkt or inactive pro-lkt protein from a lktc- mutant strain. after exposure, dna fragmentation in lymphocytes ... | 1999 | 10078599 |
| detection of haptoglobin in the high-density lipoprotein and the very high-density lipoprotein fractions from sera of calves with experimental pneumonia and cows with naturally occurring fatty liver. | in addition to the lipoprotein-deficient d > 1.25 fraction, haptoglobin was detected in the high-density lipoprotein (hdl) and the very high-density lipoprotein (vhdl) fractions from sera of calves with experimental pneumonia and cows with naturally occurring fatty liver. it was not found in the chylomicrons, very low-density lipoprotein and low-density lipoprotein fractions. washing of the hdl fraction did not decrease the haptoglobin concentration. transferrin and immunoglobulin g were immunob ... | 1999 | 10081748 |
| [long-chain fatty acids of pasteurella multocida nad pasteurella haemolytica]. | the relative contents of long-chain fatty acids in p. multocida and p. haemolytica were investigated. a dependence on the composition of the broth was established. accordingly, comparative quantitative studies on fatty acid contents have to be conducted using bacteria grown with the same lot of broth medium. as for p. multocida, there were significant differences between the serovars (c14 in tdhm and c16, delta 2c18 in bpl). these differences are, however, not significant to replace serotyping. ... | 1997 | 10084940 |
| [investigation of outer membrane proteins of pasteurella. 2: iron-regulated outer membrane proteins of pasteurella multocida and pasteurella haemolytica]. | pasteurella multocida and pasteurella haemolytica produce specific proteins in the outer membrane under iron-depleted conditions. pasteurella multocida serovar a expresses these proteins of molecular masses of 76 and 96 kda as determined by electrophoresis. the analogous serovar d produces a further iron-regulated protein of 85 kda. the pasteurella haemolytica strains of serovar a1, a6 and t contain iron-regulated outer membrane proteins of molecular masses of 71, 77 and 100 kda. these proteins ... | 1997 | 10084945 |
| efficacy of sustained release needle-less ceftiofur sodium implants in treating calves with bovine respiratory disease. | three experiments were conducted to determine preliminary efficacy of sustained release needle-less implants in effecting cure in calves with bovine respiratory disease. one hundred and twenty beef calves with a rectal temperature > or = 40 degrees c and shallow or labored respiration and coughing were used in these experiments. four groups (1-ceftiofur sodium injections [days 1, 2, and 3], 2-ceftiofur sodium needle-less implants [days 1, 2, and 3], 3-ceftiofur sodium needle-less implants [days ... | 1999 | 10085771 |
| 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 ... | 1999 | 10089159 |
| regulation of capsular polysialic acid biosynthesis by temperature in 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. the production of this polymer is strictly regulated by the growth temperature and above 40 degrees c no production is detected. analysis of the enzymatic activities directly involved in its biosynthesis reveals that neu5ac lyase, cmp-neu5ac synthetase and polysialyltransferase are involved in this regulation. very low activities were found in p. ha ... | 1999 | 10094482 |
| role of intracellular calcium in pasteurella haemolytica leukotoxin-induced bovine neutrophil leukotriene b4 production and plasma membrane damage. | isolated neutrophils were used to study the intracellular calcium ([ca2+]i) dependency of pasteurella haemolytica leukotoxin-induced production of leukotriene b4 and plasma membrane damage. exposure of neutrophils to leukotoxin caused a rapid and concentration-dependent increase in [ca2+]i, followed by simultaneous plasma membrane damage and production of leukotriene b4. removal of extracellular ca2+, replacement of ca2+ with other divalent cations, or exposure to high concentration of verapamil ... | 1999 | 10188239 |
| 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 ... | 1999 | 10189196 |
| cellular and humoral responses in the respiratory tract of goats following intranasal stimulation using formalin-killed pasteurella haemolytica a2. | a study to determine the immunoglobulin and cellular responses in the respiratory tract of goats following intranasal exposures to formalin-killed pasteurella haemolytica a2 was carried out. forty-two goats were divided into two groups. goats in group 1 were subjected to double intranasal exposures to formalin-killed p. haemolytica a2 while goats in group 2 were the unexposed control. prior to and at weekly intervals post-exposure, three goats from each group were killed, serum samples were coll ... | 1999 | 10189198 |