Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| effects of the synthetic selectin inhibitor tbc1269 on tissue damage during acute mannheimia haemolytica-induced pneumonia in neonatal calves. | to determine effects of the selectin inhibitor tbc1269 on neutrophil-mediated pulmonary damage during acute mannheimia haemolytica-induced pneumonia in newborn calves. | 2001 | 11197553 |
| a putative iron-regulated tonb-dependent receptor of mannheimia (pasteurella) haemolytica a1: possible mechanism for phase variation. | a recombinant plasmid that codes for a novel iron receptor protein (irp) of mannheimia (pasteurella) haemolytica a1 was isolated by the partial complementation of an escherichia coli fur mutant. the deduced amino acid sequence of irp exhibited characteristics typical of tonb-dependent receptors. these include: a tonb-box at the n-terminal; a 50 amino acid region homologous to the "plug" domain of the e. coli fhua and fepa receptors; and a c-terminal tonb-dependent signature which likely function ... | 2002 | 11731159 |
| phenotypic and genotypic characterization of mannheimia (pasteurella) haemolytica-like strains isolated from diseased animals in denmark. | trehalose-negative strains of the pasteurella haemolytica complex have recently been transferred to a new genus, mannheimia. this genus presently consists of five named species: m. haemolytica, m. glucosida, m. granulomatis, m. ruminalis and m. varigena. the purpose of this study was to investigate the occurrence of these species and lesions associated with these isolates in denmark. in all 106 m. haemolytica-like strains isolated from pathological material from cattle, sheep, pigs and hares sub ... | 2002 | 11731163 |
| increased anionic peptide distribution and intensity during progression and resolution of bacterial pneumonia. | anionic peptides (aps) are small anionic antimicrobial peptides composed of 7 aspartic acid residues and are produced in the lungs of humans, sheep, and cattle. although expression by epithelial cells of some antimicrobial peptides (e.g., beta-defensins) of humans and ruminants is increased in response to acute infection, ap expression is not increased during acute infection, which suggests that the expression of the latter peptide is constitutive. in this study, the degree of ap expression duri ... | 2002 | 11777825 |
| outer membrane-like vesicles secreted by actinobacillus actinomycetemcomitans are enriched in leukotoxin. | actinobacillus actinomycetemcomitans is associated with early onset periodontal diseases and secretes membranous vesicles that appear to contain several virulence-associated proteins. however, the composition of these vesicles and the process leading to their secretion are not well defined. electron micrographs of thin sectioned bacterial cells and purified vesicle preparations showed that vesicles are spherical lipid bilayers, 50-100 nm in diameter, that appear to form by budding from the outer ... | 2002 | 11782116 |
| studies on the production of quorum-sensing signal molecules in mannheimia haemolytica a1 and other pasteurellaceae species. | the bioluminescence assay system using vibrio harveyi reporter strains were used to examine quorum-sensing autoinducer (ai) activity from mannheimia haemolytica a1 cell-free culture supernatant. we showed that m. haemolytica a1 cell-free culture supernatant contains molecules that can stimulate the quorum-sensing system that regulates the expression of the luciferase operon in v. harveyi. specifically, m. haemolytica a1 can stimulate only the quorum system 2 but not system 1, suggesting that the ... | 2002 | 11786252 |
| nucleotide sequence and organization of plasmid pmvscs1 from mannheimia varigena: identification of a multiresistance gene cluster. | a small resistance plasmid of mannheimia varigena was analysed with regard to its gene organization and the development of a multiresistance gene cluster. | 2002 | 11815584 |
| effect of experimental infection of cattle with bovine herpesvirus-1 (bhv-1) on the ex vivo interaction of bovine leukocytes with mannheimia (pasteurella) haemolytica leukotoxin. | mannheimia (pasteurella) haemolytica a1 produces an extracellular leukotoxin (lkt) that is reported to bind the beta(2)-integrin cd11a/cd18 (lea-1) on ruminant leukocytes. lkt binding induces activation, and subsequent cytolysis, of these cells. it is well known that active viral infection greatly increases the susceptibility of cattle to pasteurellosis. to better understand the mechanism by which this occurs, we investigated the effects of experimental in vivo infection of cattle with bovine he ... | 2002 | 11825601 |
| effects of vaccination prior to transit and administration of florfenicol at time of arrival in a feedlot on the health of transported calves and detection of mannheimia haemolytica in nasal secretions. | to determine effects of vaccination prior to transit and prophylactic administration of florfenicol at time of arrival at a feedyard on health of cattle and colonization of the nasopharynx by mannheimia haemolytica (mh). | 2002 | 11843126 |
| demonstration of bovine herpesvirus type 1 and mannheimia haemolytica antigens in specimens stored for up to 22 months in buffered formalin. | bovine herpesvirus type 1 (bhv-1) and mannheimia haemolytica antigens were demonstrated in lung tissues that were stored in 10% neutral phosphate buffered formalin for 1 to 22 months using the immunoperoxidase method. there were no differences observed in terms of labelling intensity and distribution of m. haemolytica antigens between specimens stored for 1 and 22 months. the labeling intensity in sections from 2-cm thick specimens was comparable to those from 0.2-cm thick specimens. there was n ... | 2002 | 11858651 |
| prevalence of a novel capsule-associated lipoprotein among pasteurellaceae pathogenic in animals. | capsular serotype a strains of pasteurella multocida of avian origin express a 40-kda lipoprotein (plp-40) thought to attach the extracellular polysaccharide to the cell surface. the objective of the present study was to assess the prevalence of plp-40 in p. multocida strains of disparate serotypes and host origins, as well as other pathogenic members of the family pasteurellaceae. exponential-phase reference and clinical isolates were radiolabeled with [3h]-palmitate, lysed to obtain whole-cell ... | 2002 | 11910502 |
| in vitro evaluation of the role of platelet-activating factor and interleukin-8 in mannheimia haemolytica-induced bovine pulmonary endothelial cell injury. | to develop an in vitro model of the bovine alveolar-capillary interface and to evaluate the roles of interleukin-8 (il-8) and platelet-activating factor (paf) in neutrophil-mediated endothelial injury induced by infection with mannheimia haemolytica. | 2002 | 11911574 |
| clinical efficacy of florfenicol in the treatment of calf respiratory tract infections. | this paper reports on a study of the aetiology of calf pneumonia and the clinical efficacy of florfenicol, a new antibiotic in turkey. twenty-seven weaned and unweaned calves (13 males and 14 females) between 1 and 16 months of age brought to the clinics of selçuk university, faculty of veterinary science. broncho-alveolar lavage (bal) fluid samples were taken from the animals diagnosed to have upper respiratory tract infection associated with bronchitis (n=2), bronchitis (n=5), bronchopneumonia ... | 2002 | 11918177 |
| construction and characterization of an acapsular mutant of mannheimia haemolytica a1. | the nmaa and nmab genes, which code for udp-glcnac-2-epimerase and udp-mannac-dehydrogenase, respectively, are involved in capsular polysaccharide biosynthesis in mannheimia haemolytica a1. a chloramphenicol resistance (cm(r)) cassette cloned behind an m. haemolytica a1 promoter, plpcat, was created and used to interrupt nmaa and nmab. a 1.3-kbp dna fragment that encompasses part of nmaa and nmab was replaced by the 1.0-kbp plpcat, resulting in a knockout mutant which is cm(r) and unable to synt ... | 2002 | 11953404 |
| isolation and characterization of a new succinic acid-producing bacterium, mannheimia succiniciproducensmbel55e, from bovine rumen. | a novel succinic acid-producing bacterium was isolated from bovine rumen. the bacterium is a non-motile, non-spore-forming, mesophilic and capnophilic gram-negative rod or coccobacillus. phylogenetic analysis based on the 16s rrna sequence and physiological analysis indicated that the strain belongs to the recently reclassified genus mannheimia as a novel species, and has been named mannheimia succiniciproducens mbel55e. under 100% co(2) conditions, it grows well in the ph range of 6.0-7.5 and p ... | 2002 | 11956751 |
| biofilm bacteria: formation and comparative susceptibility to antibiotics. | the calgary biofilm device (cbd) was used to form bacterial biofilms of selected veterinary gram-negative and gram-positive pathogenic bacteria from cattle, sheep, pigs, chicken, and turkeys. the minimum inhibitory concentration (mic) and minimum biofilm eradication concentration (mbec) of ampicillin, ceftiofur, cloxacillin, oxytetracycline, penicillin g, streptomycin, tetracycline, enrofloxacin, erythromycin, gentamicin, tilmicosin, and trimethoprim-sulfadoxine for gram-positive and -negative b ... | 2002 | 11989739 |
| [consequences of short term fluctuations of the environmental temperatures in calves--part 2: effects on the health status of animals within three weeks after exposure]. | the aim of the present study was to examine consequences of sudden changes in ambient temperature over a 4-hour period (see part 1 [elmer & reinhold, 2002]) on respiratory health in clinically healthy calves. therefore, the relationship between short-term changes in ambient temperature and the occurrence of clinical respiratory disease was checked over a period of 3 weeks after exposure in 10 calves exposed to 5 degrees c, in 9 calves exposed to 35 degrees c and in 8 control calves (kept at 18-2 ... | 2002 | 11998372 |
| p53 and c-myc activation by pasteurella haemolytica leukotoxin is correlated with bovine mononuclear cells apoptosis. | to analyse the role of pasteurella haemolytica leukotoxin (lkt) in the mechanism of apoptotic cell death of bovine lymphocytes, we evaluated dna fragmentation and p53 and c-myc expression. p. haemolytica strain atcc 14003 was cultivated for lkt production. dna fragmentation was analysed by electrophoresis on agarose gel. dna strand breaks in individual apoptotic cells were also detected by an in situ terminal deoxy nucleotidyl transferase (tdt). the polymerase chain reaction (pcr) procedure was ... | 2002 | 12019726 |
| nitric oxide production as an indication of mycobacterium bovis infection in white-tailed deer (odocoileus virginianus). | white-tailed deer (odocoileus virginianus) are reservoirs for mycobacterium bovis in northeast michigan, usa. production of nitric oxide (no) by activated macrophages is a potent mechanism of mycobacterial killing. the capacity of macrophages to produce no, however, varies among mammalian species. the objective of this study was to determine if mononuclear cells from white-tailed deer produce nitrite as an indication of no production and, if so, is no produced in response to stimulation with m. ... | 2002 | 12038133 |
| dose determination and confirmation for ceftiofur crystalline-free acid administered in the posterior aspect of the ear for control and treatment of bovine respiratory disease. | three studies were conducted to determine and confirm the effective dosage rate of ceftiofur crystalline-free acid sterile suspension (ccfa-ss, 200 mg ceftiofur equivalents [ce]/ml), a long-acting ceftiofur formulation, for control and treatment of bovine respiratory disease (brd). in each study, ccfa-ss was administered once by subcutaneous (sc) injection in the middle third of the posterior aspect of the ear. study 1 was conducted using an intratracheal challenge with mannheimia (formerly past ... | 2002 | 12050825 |
| pharmacokinetics and pharmacokinetic/pharmacodynamic integration of marbofloxacin in calf serum, exudate and transudate. | marbofloxacin is a fluoroquinolone antimicrobial drug used in cattle for the treatment of respiratory infections. in this investigation the pharmacokinetics (pk) of marbofloxacin were determined after intravenous and intramuscular dosing at a dosage of 2 mg/kg. in addition the ex vivo pharmacodynamics (pd) of the drug were determined in serum and three types of tissue cage fluid (transudate, inflammatory exudate generated by carrageenan and exudate generated by lipopolysaccharide). marbofloxacin ... | 2002 | 12081611 |
| dose determination and confirmation of a long-acting formulation of ceftiofur (ceftiofur crystalline free acid) administered subcutaneously for the treatment of bovine respiratory disease. | the objective of this work was to determine and confirm an effective dose of ceftiofur crystalline free acid sterile oil suspension (ccfa-ss, 100 mg ceftiofur equivalents (ce)/ml], a long-acting single-administration ceftiofur formulation, for the treatment of the bacterial component of bovine respiratory disease (brd). study 1 was a dose determination study that used an intratracheal mannheimia haemolytica (pasteurella haemolytica) challenge model to evaluate single-administration doses of ccfa ... | 2002 | 12081612 |
| inflammatory cytokines enhance the interaction of mannheimia haemolytica leukotoxin with bovine peripheral blood neutrophils in vitro. | mannheimia (pasteurella) haemolytica a1 produces several virulence factors that play an important role in the pathogenesis of bovine pneumonic pasteurellosis. foremost among these is a leukotoxin (lkt) that specifically kills ruminant leukocytes. recent evidence suggests that m. haemolytica lkt binding to bovine leukocytes is mediated by the beta(2)-integrin cd11a/cd18 (lymphocyte function-associated antigen 1 [lfa-1]), which subsequently induces activation and cytolysis of these cells. inflamma ... | 2002 | 12117943 |
| antimicrobial anionic peptide binds in vivo to mannheimia (pasteurella) haemolytica attached to ovine alveolar epithelium. | endogenous antimicrobial peptide activity in vivo has rarely been demonstrated. to assess this, mannheimia haemolytica (log(10) 10.20 cfu) was deposited into the lungs of adult sheep, which were killed at 0, 5, 10 and 20 min for necropsy. at 0 min, m. haemolytica appeared normal and monoclonal antibody to antimicrobial anionic peptide (ap) and protein a-colloidal gold identified ap already bound to the bacterial surface. at 5-20 min, many organisms were distorted with flocculated intracellular c ... | 2002 | 12127715 |
| evaluation of health status of calves and the impact on feedlot performance: assessment of a retained ownership program for postweaning calves. | the objective of this study was to evaluate animal health status at entry to a feedlot against feedlot performance and carcass value. there were 24 herds represented by 417 calves in a retained ownership program. the health status at entry was represented by the levels of serum antibody to infectious bovine rhinotracheitis virus (ibrv), bovine viral diarrhea viruses 1 and 2 (bvdv1a, bvdv2), parainfluenza 3 virus (pi3v), bovine respiratory syncytial virus (brsv), mannheimia haemolytica, and paste ... | 2002 | 12146889 |
| bovine viral diarrhea virus (bvdv) 1b: predominant bvdv subtype in calves with respiratory disease. | the prevalence of bovine viral diarrhea virus (bvdv) infections was determined in 2 groups of stocker calves with acute respiratory disease. both studies used calves assembled after purchase from auction markets by an order buyer and transported to feedyards, where they were held for approximately 30 d. in 1 study, the calves were mixed with fresh ranch calves from a single ranch. during the studies, at day 0 and at weekly intervals, blood was collected for viral antibody testing and virus isola ... | 2002 | 12146890 |
| characterization of a bacteriocin produced by a newly isolated bacillus sp. strain 8 a. | the aim of this research was to investigate the production of bacteriocins by bacillus spp. isolated from native soils of south of brazil. | 2002 | 12174052 |
| phenotypic characterisation of australian sheep and cattle isolates of mannheimia haemolytica, mannheimia granulomatis and mannheimia varigena. | to perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic pasteurella-actinobacillus and obtained from cattle and sheep. | 2002 | 12180887 |
| pharmacokinetic and pharmacodynamic profiles of danofloxacin administered by two dosing regimens in calves infected with mannheimia (pasteurella) haemolytica. | the pharmacokinetics and pharmacodynamics of danofloxacin in calves with induced mannheimia (pasteurella) haemolytica pneumonia were evaluated. calves received either saline as an intravenous (iv) bolus or danofloxacin (0.738 mg/kg of body weight) administered as either a single iv bolus or a 36-h continuous iv infusion. blood samples and bronchial secretions were collected before and at predetermined times over 48 h following the start of treatment. calves were assessed clinically throughout, a ... | 2002 | 12183261 |
| bovine cd18 is necessary and sufficient to mediate mannheimia (pasteurella) haemolytica leukotoxin-induced cytolysis. | leukotoxin (lkt) secreted by mannheimia (pasteurella) haemolytica is an rtx toxin which is specific for ruminant leukocytes. lkt binds to beta(2) integrins on the surface of bovine leukocytes. beta(2) integrins have a common beta subunit, cd18, that associates with three distinct alpha chains, cd11a, cd11b, and cd11c, to give rise to three different beta(2) integrins, cd11a/cd18 (lfa-1), cd11b/cd18 (mac-1), and cd11c/cd18 (cr4), respectively. our earlier studies revealed that lkt binds to all th ... | 2002 | 12183553 |
| repeated intravenous doses of all-trans-retinoyl beta-d-glucuronide is not effective in the treatment of bacterial bronchopneumonia in lambs but is devoid of gross and acute toxicity. | all-trans-retinoyl beta-d-glucuronide, a water-soluble glucuronic acid conjugate of all-trans-retinoic acid, has demonstrated high biological activity and low toxicity in most in vitro and in vivo models. since the reparative effects of retinoids on epithelium are well-known, our aim was to study the effect(s) of intravenously-administered all-trans-retinoyl beta-d-glucuronide in lambs with chronic bacterial bronchopneumonia. | 2002 | 12218935 |
| mannheimia haemolytica serotype 1 and pasteurella trehalosi serotype 10 culture supernatants contain fibrinogen-binding proteins. | fibrinogen-binding proteins were found in the culture supernatants of mannheimia haemolytica serotype 1 (atcc 43270) and pasteurella trehalosi serotype 10 (eco-100). sheep fibrinogen was biotinylated and shown to bind to proteins in the culture supernatants by modified western blot. fibrinogen-binding proteins in the culture supernatant may be important virulence factors leading to the characteristic fibrinous pneumonia caused by these organisms and may be critical antigenic targets for immune p ... | 2002 | 12406660 |
| isolation of mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in belgium. | between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six mycoplasma species. attempts were made to detect mycoplasma canis, mycoplasma dispar and ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. in healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, mycoplasma bovirhinis wa ... | 2002 | 12418530 |
| coinfection with bhv-1 modulates cell adhesion and invasion by p. multocida and mannheimia (pasteurella) haemolytica. | viruses are thought to facilitate bacterial infections of the respiratory tract. the present study shows the effect of bhv-1 on pasteurella multocida and mannheimia haemolytica adherence and invasion of mdbk cells. the virus-infected mdbk cells become more susceptible to the adherence of both species of pasteurella. the observed adherence increase depends on the length of virus pre-incubation time and on virus concentration. when mdbk cells are not infected with virus, they are only invaded by p ... | 2002 | 12437222 |
| a selectin inhibitor decreases neutrophil infiltration during acute mannheimia haemolytica pneumonia. | the degree to which the selectin inhibitor tbc1269 reduces neutrophil infiltration in specific microscopic locations of the lung during acute pneumonia of neonates was determined. neonatal calves were inoculated intrabronchially with mannheimia (pasteurella) haemolytica or saline, and lung tissue was collected at 2 and 6 hours postinoculation (pi). one 6-hour group inoculated with m. haemolytica received tbc1269 intravenously before and after inoculation with m. haemolytica. infiltrates of neutr ... | 2002 | 12450200 |
| cellular distribution of anionic antimicrobial peptide in normal lung and during acute pulmonary inflammation. | anionic peptides (aps) are small antimicrobial peptides present in human and ovine lung. in this study aps were also detected in bovine lung, and production of aps in lungs with acute inflammation induced by various stimuli was determined. the distribution and intensity of aps were determined by immunohistochemistry in lungs of 1) neonatal calves (1-3 days of age) inoculated with mannheimia (pasteurella) haemolytica, a known inducer of the bovine beta-defensin lingual antimicrobial peptide (lap) ... | 2002 | 12450201 |
| mosaic structure and molecular evolution of the leukotoxin operon (lktcabd) in mannheimia (pasteurella) haemolytica, mannheimia glucosida, and pasteurella trehalosi. | the mosaic structure and molecular evolution of the leukotoxin operon (lktcabd) was investigated by nucleotide sequence comparison of the lktc, lktb, and lktd genes in 23 mannheimia (pasteurella) haemolytica, 6 mannheimia glucosida, and 4 pasteurella trehalosi strains. sequence variation in the lkta gene has been described previously (r. l. davies et al., j. bacteriol. 183:1394-1404, 2001). the leukotoxin operon of m. haemolytica has a complex mosaic structure and has been derived by extensive i ... | 2002 | 11741868 |
| leukotoxins of gram-negative bacteria. | leukotoxins are a group of exotoxins that produce their primary toxic effects against leukocytes, especially polymorphonuclear cells (pmns). leukotoxins include a variety of chemicals ranging from 9,10-epoxy 12-octadecenoate, a fatty acid derivative secreted by leukocytes themselves, to proteins such as rtx (repeats in toxin). this review focuses on leukotoxins of three species of gram-negative bacteria, mannheimia (pasteurella) haemolytica, actinobacillus actinomycetemcomitans, and fusobacteriu ... | 2002 | 11750142 |
| isolation of immunogenic outer membrane proteins from mannheimia haemolytica serotype 1 by use of selective extraction and immunoaffinity chromatography. | to use antibodies produced by calves in response to infection with mannheimia haemolytica in immunoaffinity chromatography for the identification and subsequent isolation of the dominant immunogenic antigens from bacteria grown in iron-deficient media. | 2002 | 12492276 |
| role of mannheimia haemolytica leukotoxin in the pathogenesis of bovine pneumonic pasteurellosis. | bovine pneumonic pasteurellosis continues to be a major respiratory disease in feedlot cattle despite the recent advances in our understanding of the underlying complexities of causation. the etiological agent, mannheimia haemolytica, possesses several virulence factors, including capsule, outer membrane proteins, adhesins, neuraminidase, endotoxin and exotoxic leukotoxin. accumulating scientific evidence implicates leukotoxin as the primary factor contributing to clinical presentation and lung ... | 2002 | 12665107 |
| effect of tilmicosin on chemotactic, phagocytic, and bactericidal activities of bovine and porcine alveolar macrophages. | to evaluate chemotactic, phagocytic, and bactericidal activities of bovine and porcine alveolar macrophages (am) exposed to tilmicosin. | 2002 | 16206777 |
| characterization of pasteurella spp isolated from healthy domestic pack goats and evaluation of the effects of a commercial pasteurella vaccine. | to characterize pasteurella spp isolated from healthy pack goats and evaluate the effects of administration of a commercial pasteurella vaccine. | 2002 | 16206792 |
| the influence of transport stress on the humoral immunological response of calves induced by mannheimia haemolytica leukotoxin. | in the contemporary systems of cattle production, transport stress is the most essential poly-etiological factor responsible for inducing unfavourable reactions in the animals. the main reason for this phenomenon is the immunosuppressive effect of steroid hormones on cellular and humoral protective mechanisms. the purpose of the present study was to establish the relationship between the cortisol concentration as an indicator of the stress reaction occuring directly after the transportation of c ... | 2003 | 12675467 |
| association of lps chemotype of mannheimia (pasteurella) haemolytica a1 with disease virulence in a model of ovine pneumonic pasteurellosis. | host responses during pneumonic pasteurellosis were compared in sheep infected with strains of mannheimia (pasteurella) haemolytica a1 differing in their o-antigen type. nine-week-old, specific pathogen-free lambs were infected intratracheally with parainfluenza type 3 virus (10(8) tcid(50)) followed 7 days later by 5-6 x 10(7) cfu of m. haemolytica a1 possessing rough (group r, 6 lambs) or smooth (group s, 6 lambs) lipopolysaccharide, or saline (group c, 4 lambs). group c lambs remained afebril ... | 2003 | 12691615 |
| coordinated expression of tracheal antimicrobial peptide and inflammatory-response elements in the lungs of neonatal calves with acute bacterial pneumonia. | lung tissue removed from neonatal calves with acute mannheimia haemolytica pneumonia showed that rapid up-regulation of the basal mrna expression of tracheal antimicrobial peptide (tap), nf-kappa b, and intercellular adhesion molecule 1 occurred after infection; tap and interleukin 8 expression were highly correlated. this work suggests that the coordinated expression of beta-defensin and inflammatory elements occurs during bacterial pneumonia. | 2003 | 12704177 |
| efficacy of recombinant sialoglycoprotease in protection of cattle against pneumonic challenge with mannheimia (pasteurella) haemolytica a1. | secreted recombinant sialoglycoprotease fusion protein (gcp-f) of mannheimia (pasteurella) haemolytica a1 was examined for its ability to protect cattle from experimental challenge with m. haemolytica a1. five m. haemolytica vaccines were compared including gcp-f, logarithmic phase culture supernate (presponse) and presponse enriched with gcp-f, recombinant leukotoxin (rlkt) or both. all calves receiving gcp-f had significant serum antibody responses to this antigen, measured by elisa, prior to ... | 2003 | 12706675 |
| pharmacokinetic-pharmacodynamic integration of danofloxacin in the calf. | the pharmacokinetics and pharmacodynamics of danofloxacin were studied in calves after intravenous (iv) and intramuscular (im) administration, at a dose of 1.25 mg/kg in a two period cross-over study, using tissue cages to monitor aspects of extravascular distribution. danofloxacin had a high volume of distribution (3.90 l/kg) and relatively rapid clearance (1.02 l/kgh) after iv dosing. terminal half-life was 2.65 and 4.03 h, respectively, after iv and im administration. danofloxacin penetrated ... | 2003 | 12726744 |
| biological effects of two genetically defined leukotoxin mutants of mannheimia haemolytica. | mannheimia(pasteurella)haemolytica serotype 1 is the primary causative agent responsible for bovine pneumonic mannheimiosis, also known as shipping fever in cattle. the bacterium produces a variety of virulence factors, foremost of which is the exotoxic leukotoxin. the leukotoxin is a calcium-dependent cytolysin that is a member of the rtx (repeats in toxin) family and exhibits a narrow cell-type and species specificity and has biological effects only on ruminant leukocytes and platelets. the ge ... | 2003 | 12732470 |
| effect of intranasal exposure to leukotoxin-deficient mannheimia haemolytica at the time of arrival at the feedyard on subsequent isolation of m haemolytica from nasal secretions of calves. | to determine the effect of intranasal exposure to live leukotoxin (lkta)-deficient mannheimia haemolytica (mh) at the time of feedyard arrival on nasopharyngeal colonization by wild-type mh in calves. | 2003 | 12755298 |
| the effects of danofloxacin and tilmicosin on neutrophil function and lung consolidation in beef heifer calves with induced pasteurella (mannheimia) haemolytica pneumonia. | pneumonia caused by pasteurella (mannheimia) haemolytica was induced in weaned beef heifer calves, approximately 6 months of age. calves were treated at 20 h after challenge with therapeutic doses of danofloxacin or tilmicosin. peripheral blood neutrophils were collected at 3, 24 and 48 h after treatment. the ex vivo effects on neutrophil function, neutrophil apoptosis, and hematological parameters were examined, as was the effect on percentage lung consolidation. neutrophil function assays incl ... | 2003 | 12755900 |
| prior exposure to mannheimia haemolytica leukotoxin or lps enhances beta(2)-integrin expression by bovine neutrophils and augments lkt cytotoxicity. | mannheimia (pasteurella) haemolytica serotype1 produces a variety of virulence factors that play an important role during the pathogenesis of bovine pneumonic pasteurellosis. among these, a leukotoxin (lkt) and lipopolysaccharide (lps) are thought to be the primary virulence factors that contribute to the characteristic pathology of pasteurellosis. recent evidence suggests that m. haemolytica lkt binding to bovine leukocytes is mediated by the beta(2)-integrin cd11a/cd18 (lfa-1), which subsequen ... | 2003 | 12782479 |
| immunogenicity of recombinant mannheimia haemolytica serotype 1 outer membrane protein plpe and augmentation of a commercial vaccine. | mannheimia haemolytica is the major cause of severe bacterial pneumonia associated with shipping fever in cattle. the gene for m. haemolytica outer membrane protein (omp) plpe was cloned into the expression vector prseta. the cloned gene was then expressed in bl21(de3)plyss and the recombinant plpe (rplpe) was purified and used in immunological and vaccination studies. vaccination of cattle with commercial m. haemolytica vaccines stimulated no significant (p>0.05) antibody responses to rplpe. re ... | 2003 | 12798623 |
| response of calves persistently infected with noncytopathic bovine viral diarrhea virus (bvdv) subtype 1b after vaccination with heterologous bvdv strains in modified live virus vaccines and mannheimia haemolytica bacterin-toxoid. | seronegative persistently infected (pi) calves with bovine viral diarrhea virus (bvdv) subtype 1b were vaccinated with each of four modified live virus (mlv) bvdv vaccines and a mannheimia haemolytica bacterin-toxoid. nasal swabs and peripheral blood leukocytes (pbl) were collected for virus isolation and serums were collected after vaccination and tested for bvdv1a, bvdv1b, bvdv2, bovine herpesvirus-1 (bhv-1), bovine parainfluenza-3 virus (pi-3v), and bovine respiratory syncytial virus (brsv) a ... | 2003 | 12798641 |
| evaluation of diagnostic procedures for subclinical mastitis in meat-producing sheep. | samples of foremilk were collected from 261 clinically normal glands of 150 ewes, and tested using the california mastitis test (cmt). further samples were collected from 195 of these glands for determination of automated somatic cell counts (scc), and from 60 of these glands for bacteriological assessment. the sensitivity and specificity of cmt for detecting samples with scc above different threshold levels and for cmt and scc in determining bacteriological status were evaluated using two-graph ... | 2003 | 12800867 |
| mannheimia haemolytica leukotoxin-induced increase in leukotriene b4 production by bovine neutrophils is mediated by a sustained and excessive increase in intracellular calcium concentration. | isolated bovine neutrophils were used to study the relationship between the duration and magnitude of the mannheimia haemolytica leukotoxin-induced increase in intracellular calcium concentration and leukotriene b4 synthesis. in contrast to recombinant human c5a, which caused a transient, small increase in intracellular calcium concentration and no effects on leukotriene b4 synthesis, exposure of neutrophils to leukotoxin resulted in a rapid, sustained, large increase in intracellular calcium co ... | 2003 | 12855172 |
| pharmacokinetic/pharmacodynamic relationship of danofloxacin against mannheimia haemolytica in a tissue-cage model in calves. | to evaluate an experimental model of the pharmacokinetic/pharmacodynamic (pk/pd) relationship of danofloxacin against mannheimia haemolytica infection, using subcutaneously implanted tissue cages in calves. | 2003 | 12865390 |
| in vitro activities of florfenicol against bovine and porcine respiratory tract pathogens. | florfenicol in vitro activities for a total of 756 bacterial isolates from respiratory tract infections of cattle and swine were comparatively investigated by the agar diffusion method and the microdilution broth method. florfenicol showed high in vitro activity against pasteurella multocida, mannheimia haemolytica, actinobacillus pleuropneumoniae, and streptococcus suis, with all of the isolates inhibited by </=2 micro g of florfenicol per ml. | 2003 | 12878547 |
| crystal structure of pasteurella haemolytica ferric ion-binding protein a reveals a novel class of bacterial iron-binding proteins. | pasteurellosis caused by the gram-negative pathogen pasteurella haemolytica is a serious disease leading to death in cattle. to scavenge growth-limiting iron from the host, the pathogen utilizes the periplasmic ferric ion-binding protein a (phfbpa) as a component of an atp-binding cassette transport pathway. we report the 1.2-a structure of the iron-free (apo) form of phfbpa, which is a member of the transferrin structural superfamily. the protein structure adopts a closed conformation, allowing ... | 2003 | 12882966 |
| contribution of intracellular calcium stores to an increase in cytosolic calcium concentration induced by mannheimia haemolytica leukotoxin. | the contribution of intracellular calcium stores to mannheimia haemolytica leukotoxin (lkt)-induced increase in cytosolic calcium concentration was studied by pharmacologically inhibiting transport of calcium across the plasma and endoplasmic reticulum membranes of bovine neutrophils exposed to lkt. active intracellular storage of calcium by sarcoplasmic/endoplasmic reticulum calcium atpase, influx of extracellular calcium across the plasma membrane, and release of stored calcium via inositol tr ... | 2003 | 12900016 |
| the acute phase response in calves experimentally infected with bovine viral diarrhoea virus and/or mannheimia haemolytica. | the aim of this investigation was to study differences and similarities in the acute phase response of calves experimentally infected in the respiratory tract with either bovine viral diarrhoea virus (bvdv) or mannheima haemolytica (mh), or with a combination of both (bvdv/mh). a non-inoculated control group was also included. the acute phase response was measured by serum or plasma concentrations of the acute phase proteins (apps) haptoglobin, serum amyloid a (saa) and fibrinogen, and of cortis ... | 2003 | 12916692 |
| pasteurella multocida- and pasteurella haemolytica-ghosts: new vaccine candidates. | pasteurella multocida is an important animal pathogen. bacterial ghosts produced by the expression of phage phix174 lysis gene e are empty cells devoid of cytoplasmic and genomic material. lysis of p. multocida 7a and p. haemolytica a1 carrying pasteurella-specific lysis vectors (psr2 and pson2) occurred 140 min after induction of gene e expression induced by temperature upshift. the e-mediated cell lysis and killing activity was the same in both pasteurella species and no viable cells could be ... | 2003 | 12922135 |
| pasteurella haemolytica in human urine. | pasteurella haemolytica was isolated from a human urine specimen. this unusual human pathogen showed a mucoid colony with a modest haemolysis and typical biochemical characteristics. api 20e and api 20ne identified the bacterium as pasteurella spp. and p. haemolytica, respectively. to the authors' knowledge, this is the first reported case of p. haemolytica in human urine. | 2003 | 14514157 |
| a tissue cage model in calves for studies on pharmacokinetic/pharmacodynamic interactions of antimicrobials. | an in vivo model for studies of pharmacokinetic/pharmacodynamic (pk/pd) interactions of antimicrobials was developed. tissue cages with a constant surface area but with different volumes were implanted in calves and infected with mannheimia haemolytica. penicillin was injected directly into the cages. with this procedure, different concentration-time profiles could be simulated so that the effect of a range of pk/pd indices on the infection could be monitored. the area under the curve to minimum ... | 2003 | 14522106 |
| batch and continuous cultures of mannheimia succiniciproducens mbel55e for the production of succinic acid from whey and corn steep liquor. | mannheimia succiniciproducens mbel55e isolated from bovine rumen is able to produce a large amount of succinic acid in a medium containing glucose, peptone, and yeast extract. in order to reduce the cost of the medium, whey and corn steep liquor (csl) were used as substrates for the production of succinic acid by m. succiniciproducens mbel55e. anaerobic batch cultures of m. succiniciproducens mbel55e in a whey-based medium containing csl resulted in the production of succinic acid with a yield o ... | 2003 | 14530958 |
| pcr-detection of hemophilus paragallinarum, hemophilus somnus, mannheimia (pasteurella) hemolytica, mannheimia spp., pasteurella trehalosi, and pasteurella multocida. | 2003 | 12512370 | |
| cytotoxic activity of mannheimia haemolytica strains in relation to diversity of the leukotoxin structural gene lkta. | the leukotoxin of mannheimia haemolytica has a very high degree of amino acid diversity because the lkta gene has a complex mosaic structure that has been derived by horizontal dna transfer and intragenic recombination. the objective of the present study was to determine the effect of this amino acid diversity on leukotoxin cytotoxicity against bovine and ovine cell types. this was done by comparing the luminol-dependent chemiluminescence response of bovine and ovine neutrophils after pre-incuba ... | 2003 | 12523988 |
| pharmacokinetics (pk), pharmacodynamics (pd), and pk-pd integration of danofloxacin in sheep biological fluids. | the fluoroquinolone antimicrobial drug danofloxacin was administered to sheep intravenously (i.v.) and intramuscularly (i.m.) at a dose of 1.25 mg/kg of body weight in a two-period crossover study. the pharmacokinetic properties of danofloxacin in serum, inflamed tissue cage fluid (exudate), and noninflamed tissue cage fluid (transudate) were established by using a tissue cage model. the in vitro and ex vivo activities of danofloxacin in serum, exudate, and transudate against a pathogenic strain ... | 2003 | 12543670 |
| effects of aerosolized dust in goats on lung clearance of pasteurella and mannheimia species. | the objective was to determine whether the inhalation of large quantities of feedyard dust predisposed the animals to pulmonary bacterial proliferation. two control groups, c1 and c2, did not receive dust treatments, and two principal groups (p1 and p2) received a total of 14 dust treatments each. the c1 and p1 groups of goats each received a transthoracic challenge of live mannheimia haemolytica (4 x 10(6) colony forming units, cfu) the c2 and p2 groups of goats each received a transthoracic ch ... | 2003 | 12567239 |
| protective immunity against pasteurellosis in cattle, induced by pasteurella haemolytica ghosts. | pasteurella haemolytica is a cattle pathogen of significant economic impact. an effective vaccine against bovine pneumonic pasteurellosis is therefore of high importance. apart from economic concerns, pasteurellosis caused by p. haemolytica is a serious disease leading to death in cattle if it remains untreated. in this study p. haemolytica-ghosts are presented as a promising vaccine candidate in cattle. to obtain sufficient vaccination material a fermentation protocol for p. haemolytica-ghost p ... | 2003 | 12615438 |
| diversity of mannheimia haemolytica and pasteurella trehalosi serotypes from apparently healthy sheep and abattoir specimens in the highlands of wollo, north east ethiopia. | the prevalence and serotypic diversity of mannheimia [pasteurella] haemolytica and pasteurella trehalosi from nasal swabs, sera and abattoir specimens from sheep in the highlands of wollo, north east ethiopia was investigated. prevalence rates of 83% and 75% of these microorganisms were found in the serum samples and nasal swabs, respectively, from apparently healthy sheep. in a local abattoir, 205 lungs were investigated, 34% of which showed pneumonia, from which samples were collected from 51 ... | 2003 | 12625399 |
| novel protease produced by a pasteurella trehalosi serotype 10 isolate from a pneumonic bighorn sheep: characteristics and potential relevance to protection. | a strain of pasteurella trehalosi serotype 10, e(co)-100, isolated from a bighorn sheep that had succumbed to pneumonic pasteurellosis during an epizootic, was compared to well-characterized strains of p. trehalosi serotype 10 and mannheimia haemolytica serotype 1. the gene for leukotoxin a (lkta) from e(co)-100 was sequenced and found to be identical on an amino acid basis to a published sequence for lkta from p. trehalosi serotype 10. however, the toxic activity in culture supernatant measured ... | 2003 | 12637002 |
| effect of interleukin-8 and granulocyte colony-stimulating factor on priming and activation of bovine neutrophils. | neutrophils are important effector cells in innate and acquired immunity, but the magnitude and character of their phagocytic and bactericidal responses depend on cues derived from mediators in the local microenvironment. this study investigated the effect of bovine interleukin-8 (il-8) and granulocyte colony-stimulating factor (g-csf) on priming and activation of bovine neutrophils in vitro and in vivo. neutrophils were isolated from blood and cultured for up to 18 h, with or without cytokines, ... | 2003 | 12654776 |
| survey of restriction-modification systems and transformation in mannheimia haemolytica and pasteurella trehalosi. | a significant obstacle to molecular studies of mannheimia (pasteurella) haemolytica, has been its resistance to genetic transformation. the lack of competence of many m. haemolytica strains has been attributed to the presence of restriction modification systems. in this study, representative strains of 12 m. haemolytica serotypes and four pasteurella trehalosi serotypes were successfully transformed by electroporation using a recombinant vector derived from the native m. haemolytica a1 serotype ... | 2003 | 12488074 |
| molecular typing of mannheimia (pasteurella) haemolytica serotype a1 isolates from cattle in japan. | pulsed field gel electrophoresis (pfge) and random amplified polymorphic dna (rapd) methods were applied for molecular typing of 130 mannheimia (pasteurella) haemolytica serotype a1 isolates obtained from 13 prefectures in japan. these isolates were divided into 15 apai pfge profiles that formed six distinct clusters (clusters a-f). fifty-three (40.7%) isolates were classified in cluster b, and 20.0, 13.8, 12.3, 6.9 and 6.1% of isolates were in clusters e, a, f, d and c, respectively. the isolat ... | 2003 | 14596536 |
| a case of pasteurella haemolytica sepsis in a patient with mitral valve disease who developed a splenic abscess. | we report a patient with sepsis caused by pasteurella haemolytica, an extremely rare etiologic agent of human infection, who had mitral valve disease and developed a splenic abscess. | 2003 | 14606620 |
| molecular characterization of plasmids with antimicrobial resistant genes in avian isolates of pasteurella multocida. | the complete nucleotide sequences of two plasmids from avian isolates of pasteurella multocida that caused outbreaks of fowl cholera in taiwan were determined. the entire sequences of the two plasmids, designated as pjr1 and pjr2, were 6792 bp and 5252 bp. sequence analysis showed that the plasmid pjr1 contained six major genes: the first gene (sulii) encoded a type ii sulfonamide resistant dihydropteroate synthase, the second gene (tetg) encoded a tetracycline resistance protein, the third gene ... | 2003 | 14708986 |
| pharmacological inhibition of mannheimia haemolytica lipopolysaccharide and leukotoxin-induced cytokine expression in bovine alveolar macrophages. | the inflammatory cytokines tumor necrosis factor-alpha (tnfalpha), interleukin-1 beta (il-1beta), and interleukin-8 (il-8) are believed to contribute to the pathogenesis of lung injury in bovine pneumonic mannheimiosis (bpm) caused by mannheimia (pasteurella) haemolytica. inflammatory cytokines may, therefore, represent therapeutic targets to be modulated for the purpose of treating or preventing this important disease of cattle. the purpose of this study was to evaluate the ability of six pharm ... | 2004 | 14726234 |
| in vitro activities of spectinomycin and comparator agents against pasteurella multocida and mannheimia haemolytica from respiratory tract infections of cattle. | prior to the renewal of spectinomycin licensing for veterinary uses in germany, 154 pasteurella multocida and 148 mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their mics of spectinomycin and other antimicrobial agents. the data obtained should serve as a baseline from which to judge the future development of resistance. moreover, the in vitro activity of spectinomycin in comparison with other antimicrobials should be assessed. | 2004 | 14729757 |
| maternally derived humoral immunity to bovine viral diarrhea virus (bvdv) 1a, bvdv1b, bvdv2, bovine herpesvirus-1, parainfluenza-3 virus bovine respiratory syncytial virus, mannheimia haemolytica and pasteurella multocida in beef calves, antibody decline by half-life studies and effect on response to vaccination. | the passive immunity transferred to calves from their dams was investigated in a beef herd to determine half-life of antibody, estimated time to seronegative status and effect on immunization. one hundred two beef calves in a commercial ranch under standard management conditions were utilized. samples were collected at branding (day 0). this was the first possible date to collect samples postcalving. this was approximately 2 months postcalving, and days 95 and 116. the calves were divided into t ... | 2004 | 14741155 |
| immune responses to bovine respiratory syncytial virus (brsv) following use of an inactivated brsv-pi3-mannheimia haemolytica vaccine and a modified live brsv-bvdv vaccine. | 2004 | 14975397 | |
| in vitro adherence and invasion of ovine mammary epithelium by mannheimia (pasteurella) haemolytica. | 2004 | 14975398 | |
| an outbreak of pneumonic pasteurellosis in sheep due to mannheimia (pasteurella) haemolytica serotype 7. | 2004 | 14975399 | |
| otitis in cattle, an aetiological review. | otitis externa in cattle has a significant impact in tropical and subtropical regions, and the aetiological agents are predominantly rhabditiform nematodes and mites of the genus raillietia. its prevalence is higher in mature and zebu cattle. in advanced clinical cases there can be irreversible and fatal neural lesions. ear infection in calves has been associated with concurrent respiratory diseases and mixed infection. the principal reported agents of otitis in calves are bacteria such as actin ... | 2004 | 14995970 |
| protective effect of dexamethasone in experimental bovine pneumonic mannheimiosis. | clinical and experimental studies provide unequivocal evidence that neutrophils participate in the pathogenesis of lung injury in bovine pneumonic mannheimiosis (bpm). since the inflammatory cytokines tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-8 play a central role in the recruitment and activation of neutrophils, we hypothesize that pharmacological inhibition of their expression may prevent or reduce the inflammatory lung injury that is characteristic of the disease. the p ... | 2004 | 15001229 |
| antigenic secreted proteins from haemophilus paragallinarum. a 110-kda putative rtx protein. | haemophilus paragallinarum is the causal agent of infectious coryza, an economically important disease for the poultry industry. this bacterium secreted proteins of 25-110 kda during its growth in brain heart infusion, tryptic soy broth, or luria-bertani glucose phosphate media, all lacking serum. some of these proteins were recognized by sera from chickens experimentally infected with h. paragallinarum. a 110-kda protein was recognized by a serum pool from convalescent-phase pigs naturally infe ... | 2004 | 15019738 |
| saccharomyces cerevisiae csm1 gene encoding a protein influencing chromosome segregation in meiosis i interacts with elements of the dna replication complex. | we present the characteristics of the csm1 (spo86) protein of saccharomyces cerevisiae that are important for meiotic division. the level of csm1p does not change throughout the cell cycle, but this protein is absent in mature spores. deletion of csm1 causes incorrect spore formation and meiotic chromosome missegregation together with increased sensitivity of vegetative cells to benomyl and manganese. in a two-hybrid analysis with csm1p as bait, we detected interactions with three members of the ... | 2004 | 15023545 |
| effects of dietary energy and starch concentrations for newly received feedlot calves: i. growth performance and health. | crossbred calves (n = 572; initial bw = 186 +/- 27 kg) purchased from northern texas, arkansas, and southeast oklahoma auction markets were delivered to the willard sparks beef research center, stillwater, ok, and used to study the effects of dietary energy and starch concentrations on performance and health of newly received feedlot calves during a 42-d receiving period. on arrival, calves were assigned randomly to one of two dietary energy levels (0.85 or 1.07 mcal neg/kg dm) and one of two di ... | 2004 | 15032441 |
| trna-intergenic spacer pcr for the identification of pasteurella and mannheimia spp. | trna-intergenic spacer pcr (tdna-pcr) was evaluated for its effectiveness in differentiating pasteurella and mannheimia (sub)species predominantly of ruminant origin. for this purpose, 38 reference strains and 13 field isolates belonging to both genera were investigated. tdna-pcr enabled discrimination of all pasteurella species tested (pasteurella (p.) aerogenes, p. avium, p. canis, p. lymphangitidis, p. multocida, p. trehalosi). for the differentiation of the subspecies of p. multocida, an add ... | 2004 | 15036534 |
| [mannheimia haemolytica and the pathogenesis of enzootic bronchopneumonia]. | mannheimia (m.) haemolytica (formerly pasteurella [p.] haemolytica) is the primary aetiological agent of pneumonic pasteurellosis--one of the most important respiratory diseases in cattle and sheep. while bovine pneumonic pasteurellosis is regarded to be mainly caused by m. haemolytica serotype a1, and in germany during the last years also by serotype a6, sheep can be infected by all serotypes although there is an increased prevalence of serotypes a2 and a5-7. the obligate pathogenicity of m. ha ... | 2004 | 15046457 |
| evaluation of mannheimia haemolytica leukotoxin prepared in nonsupplemented and bsa or fbs supplemented rpmi 1640 medium. | mannheimia haemolytica leukotoxin (lkt) is the major factor that contributes to lung injury in bovine pneumonic pasteurellosis. supernatant preparations containing lkt produced by m. haemolytica serotype 1, grown in rpmi 1640 medium supplemented with bsa or fbs and without supplements were evaluated during this study. analysis of obtained lkt showed presence of 105 kda antigen (sds-page electrophoresis). the obtained bacterial protein fraction estimated as lkt was detected by western blotting wi ... | 2004 | 15061478 |
| immunohistochemical study of hemophilus somnus, mycoplasma bovis, mannheimia hemolytica, and bovine viral diarrhea virus in death losses due to myocarditis in feedlot cattle. | the purpose of this study was to determine the presence of hemophilus somnus, mycoplasma bovis, mannheimia hemolytica, and bovine viral diarrhea virus (bvdv) in lesional tissues of feeder calves dying with myocarditis. tissues from the heart and lungs of 92 calves dying with myocarditis in alberta feedlots were immunohistochemically stained for the antigens of these agents. tissues from 44 calves dying from noninfectious causes and 35 calves dying with pneumonia were tested as controls. hemophil ... | 2004 | 15072195 |
| immunohistopathological findings in the lungs of calves naturally infected with mycoplasma bovis. | histology and immunohistochemistry were used to analyse the lesions and distribution of mycoplasma bovis antigen in the lungs of 18 naturally infected calves. microscopic examination of pneumonic lungs revealed two distinct patterns of necrosis and inflammation. the first pattern was observed in six of 18 (33.3%) calves in which microscopic lesions were characterized by large irregular areas of coagulative necrosis surrounded by a dense zone of degenerated neutrophils. moderate amounts of mycopl ... | 2004 | 15086504 |
| tilmicosin-induced bovine neutrophil apoptosis is cell-specific and downregulates spontaneous ltb4 synthesis without increasing fas expression. | the pathology of bacterial pneumonia, such as seen in the bovine lung infected with mannheimia haemolytica, is due to pathogen virulence factors and to inflammation initiated by the host. tilmicosin is a macrolide effective in treating bacterial pneumonia and recent findings suggest that this antibiotic may provide anti-inflammatory benefits by inducing polymorphonuclear neutrophilic leukocyte (pmn) apoptosis. using an in vitro bovine system, we examined the cell-specificity of tilmicosin, chara ... | 2004 | 15099497 |
| does high organochlorine (oc) exposure impair the resistance to infection in polar bears (ursus maritimus)? part i: effect of ocs on the humoral immunity. | this study was undertaken to assess if high levels of organochlorines (ocs) are associated with decreased ability to produce antibodies in free-ranging polar bears (ursus maritimus) and thus affect the humoral immunity. in 1998 and 1999, 26 and 30 polar bears from svalbard, norway, and churchill, canada, respectively, were recaptured 32-40 d following immunization with inactivated influenza virus, reovirus, and herpes virus and tetanus toxoid. blood was sampled at immunization and at recapture f ... | 2004 | 15129552 |
| bhv-1 infection and inflammatory cytokines amplify the interaction of mannheimia haemolytica leukotoxin with bovine peripheral blood mononuclear cells in vitro. | bovine herpesvirus-1 (bhv-1) has been reported to increase the susceptibility of cattle to respiratory disease caused by mannheimia (pasteurella) haemolytica a1. the principal virulence factor of m. haemolytica is a leukotoxin (lkt) that can specifically kill ruminant leukocytes following its binding to the beta2-integrin cd11a/cd18 (lymphocyte function-associated antigen 1 (lfa-1)). in this study, we investigated the effects of experimental infection of bovine peripheral blood mononuclear cells ... | 2004 | 15135985 |
| effect of danofloxacin and tilmicosin on body temperatures of beef calves with pneumonia experimentally induced by inoculation with mannheimia haemolytica. | to examine effects of danofloxacin and tilmicosin on continuously recorded body temperature in beef calves with pneumonia experimentally induced by inoculation of mannheimia haemolytica. | 2004 | 15141881 |
| bacterial ghosts are an efficient delivery system for dna vaccines. | mass implementation of dna vaccines is hindered by the requirement of high plasmid dosages and poor immunogenicity. we evaluated the capacity of mannheimia haemolytica ghosts as delivery system for dna vaccines. in vitro studies showed that bacterial ghosts loaded with a plasmid carrying the green fluorescent protein-encoding gene (pegfp-n1) are efficiently taken up by apc, thereby leading to high transfection rates (52-60%). vaccination studies demonstrated that ghost-mediated delivery by intra ... | 2004 | 15153504 |
| efficacy of danofloxacin in the treatment of respiratory disease in european cattle. | the efficacy of an injectable formulation of danofloxacin (180 mg/ml) in the treatment of naturally occurring bovine respiratory disease was evaluated in field studies on farms in france, ireland and the united kingdom. cattle aged one week to 15 months with clinical respiratory disease were randomly allocated to treatment with 6 mg/kg danofloxacin or 10 mg/kg tilmicosin, administered by a single subcutaneous injection on day 0. a second injection of danofloxacin was administered on day 2, only ... | 2004 | 15160844 |
| structural basis for iron binding and release by a novel class of periplasmic iron-binding proteins found in gram-negative pathogens. | we have determined the 1.35- and 1.45-a structures, respectively, of closed and open iron-loaded forms of mannheimia haemolytica ferric ion-binding protein a. m. haemolytica is the causative agent in the economically important and fatal disease of cattle termed shipping fever. the periplasmic iron-binding protein of this gram-negative bacterium, which has homologous counterparts in many other pathogenic species, performs a key role in iron acquisition from mammalian host serum iron transport pro ... | 2004 | 15175304 |
| experimental infectious respiratory disease in groups of calves: lobar distribution, variance, and sample-size requirements for vaccine evaluation. | the distribution and variance of respiratory disease produced with aerosols of bovine herpesvirus 1 (bhv-1) and mannheimia haemolytica in control (183 calves in 44 experiments) and vaccinated calves were studied in experiments conducted at the animal diseases research institute, lethbridge, alberta, from 1975 to 1989. all calves had been born and raised at this institute and exposed similarly for 5 min by means of a face mask to viral and bacterial aerosols produced by a collison atomizer (parti ... | 2004 | 15188956 |