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ICEPmu1, an integrative conjugative element (ICE) of Pasteurella multocida: structure and transfer.Background Integrative and conjugative elements (ICEs) have not been detected in Pasteurella multocida. In this study the multiresistance ICEPmu1 from bovine P. multocida was analysed for its core genes and its ability to conjugatively transfer into strains of the same and different genera. Methods ICEPmu1 was identified during whole genome sequencing. Coding sequences were predicted by bioinformatic tools and manually curated using the annotation software ERGO. Conjugation into P. multocida, M ...201222001176
antimicrobial susceptibility patterns and sensitivity to tulathromycin in goat respiratory bacterial isolates.bacterial pneumonia is a common and often life-threatening respiratory problem in both meat and dairy goats. options for approved antibiotic therapy in goats to combat these bacterial infections are severely limited and frequently drugs must be used in an extra-label manner. tulathromycin, a triamilide macrolide antimicrobial drug shown to be effective against swine and cattle respiratory bacterial agents, has been identified as a potentially useful drug in caprines. the present study was conduc ...201122078276
impact of isoflupredone acetate treatment on clinical signs and weight gain in weanling heifers with experimentally induced mannheimia haemolytica bronchopneumonia.objective-to characterize the impact of mannheimia haemolytica infection on feed intake and weight gain in feedlot heifers and to evaluate the clinical efficacy of isoflupredone acetate administered in combination with oxytetracycline. animals-96 weanling heifers in a research feedlot facility. procedures-bronchopneumonia was induced by intrabronchial infusion of m haemolytica. control heifers underwent a sham procedure. infected heifers were treated with oxytetracycline alone or in combinat ...201122126689
serologic response to mannheimia haemolytica in calves concurrently inoculated with inactivated or modified-live preparations of m. haemolytica and viral combination vaccines containing modified-live bovine herpesvirus type 1.to assess the serologic response of calves to inactivated and modified-live (ml) mannheimia haemolytica (mh) preparations given alone and concurrently with combination viral vaccines containing ml bovine herpesvirus type 1 (bhv-1).201122023134
plasmid-mediated florfenicol resistance in mannheimia haemolytica isolated from cattle.the aim of this study was to analyse a florfenicol-resistant mannheimia haemolytica isolated from a calf to determine the genetic basis of its florfenicol-resistance. the antimicrobial susceptibility and plasmid content of the isolate were determined. a florfenicol resistant plasmid carrying the flor gene was identified by pcr and transformed into escherichia coli jm109 and hb101 strains. the plasmid was then mapped and sequenced completely. the isolate was resistant to chloramphenicol, florfeni ...201122019290
outer membrane protein a of bovine and ovine isolates of mannheimia haemolytica is surface exposed and contains host species-specific epitopes.mannheimia haemolytica is the etiological agent of pneumonic pasteurellosis of cattle and sheep; two different ompa subclasses, ompa1 and ompa2, are associated with bovine and ovine isolates, respectively. these proteins differ at the distal ends of four external loops, are involved in adherence, and are likely to play important roles in host adaptation. m. haemolytica is surrounded by a polysaccharide capsule, and the degree of ompa surface exposure is unknown. to investigate surface exposure a ...201121896777
Colostrum from cattle immunized with a vaccine based on iron regulated proteins of Mannheimia haemolytica confers partial protection.Passive protection afforded by colostrum from cattle vaccinated prepartum with an inactivated combination vaccine against viral pathogens and Mannheimia haemolytica (M. haemolytica) was evaluated against an experimental M. haemolytica challenge. Newborn calves were either fed colostrum from vaccinated dams or control colostrum. At approximately 3 weeks of age 24 calves were experimentally infected with M. haemolytica. Animals of both groups displayed clinical signs of respiratory disease and lun ...201122154882
Pyogenic cervical spondylitis caused by Pasteurella haemolytica attributed to excessive contact with dogs.The bacterium Pasteurella haemolytica is resident in the oral cavities of dogs and cats and is often a cause of zoonotic infection. However, it is rare for it to be the pathogenic bacteria behind pyogenic spondylitis, and few studies have been conducted on it. This article reports a case of pyogenic cervical spondylitis thought to be caused by excessive contact with pet dogs.A 52-year-old man reported neck pain and pain in the right upper limb. He was admitted after plain radiographs and magneti ...201122049970
Dominant expression of interleukin-8 vs interleukin-1ß and tumour necrosis factor alpha in lungs of lambs experimentally infected with Mannheimia haemolytica.To quantify the number of cells infected with Mannheimia haemolytica and expressing interleukin (IL)-1ß, tumour necrosis factor alpha (TNFa) and IL-8 using immunohistochemistry, and to measure the immunoreactivity of cytokines in pulmonary tissue extracts using ELISA, in the lung of lambs experimentally infected with M. haemolytica, and to compare the patterns of expression of cytokines in airways at different times post-infection (p.i.).201121851299
Survey of marbofloxacin susceptibility of bacteria isolated from cattle with respiratory disease and mastitis in Europe.A monitoring programme conducted in Europe since 1994 to survey the marbofloxacin susceptibility of bacterial pathogens isolated from cattle has established the susceptibility of bacterial strains isolated before any antibiotic treatment from bovine mastitis and bovine respiratory disease (BRD) cases between 2002 and 2008. Minimum inhibitory concentration (MIC) was determined by a standardised microdilution technique. For respiratory pathogens, Pasteurella multocida and Mannheimia haemolytica is ...201122121154
Pharmacokinetic and pharmacodynamic testing of marbofloxacin administered as a single injection for the treatment of bovine respiratory disease.Vallé, M., Schneider, M., Galland, D., Giboin, H., Woehrlé, F. Pharmacokinetic and pharmacodynamic testing of marbofloxacin administered as a single injection for the treatment of bovine respiratory disease. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365-2885.2011.01350.x. New approaches in Pharmacokinetic/Pharmacodynamic (PK/PD) integration suggested that marbofloxacin, a fluoroquinolone already licensed for the treatment of bovine respiratory disease at a daily dosage of 2 mg/kg for 3-5 days, ...201122126438
efficacy and safety of a new 450 mg/ml florfenicol formulation administered intramuscularly in the treatment of bacterial bovine respiratory disease.the objective of the study was the safety and efficacy evaluation of a new 450 mg/ml florfenicol formulation in the treatment of naturally occurring respiratory disease when administered intramuscularly, compared with a positive control group treated with the well-established 300 mg/ml formulation. a total of 174 calves, selected from five sites in france and spain, aged from 1 to 17 months, showing severe signs of respiratory disease, were randomly assigned to treatment with either the 300 mg/m ...201121921060
[pilot study: serological research of bovine respiratory syncytial virus and mannheimia haemolytica in young cattle at dairy farms in the netherlands]. 201121870575
identification and immunogenicity of mannheimia haemolytica s1 outer membrane lipoprotein plpf.immunity against mannheimia haemolytica requires antibodies against leukotoxin (lkt) and bacterial cell surface antigens, most likely immunogenic outer membrane proteins (omps). five immunogenic outer membrane lipoproteins identified and characterized in m. haemolytica were designated pasteurella lipoproteins (plp) a, -b, -c, -d and -e. using immunoproteomics, we identified a heretofore-uncharacterized m. haemolytica immunogenic outer membrane lipoprotein that we designated plpf, which was previ ...201121875637
Pathology in practice. Mannheimia haemolytica. 201122087719
a proteomic analysis of the regulon of the narp two-component regulatory system response regulator in the bovine pathogen mannheimia haemolytica a1.abstract:201122114901
comparison of antemortem antimicrobial treatment regimens to antimicrobial susceptibility patterns of postmortem lung isolates from feedlot cattle with bronchopneumonia.a retrospective study was performed to compare the treatment regimens in feedlot cattle that died with bovine respiratory disease (brd) to the antimicrobial susceptibility patterns of the microorganisms isolated from lungs. forty-three cattle submitted by the willard sparks beef research center (wsbrc) to the oklahoma animal disease diagnostic laboratory for postmortem examination during 2007 had bronchopneumonia (acute = 16, subacute = 5, or chronic = 22). lungs from cattle were cultured aerobi ...201122362524
cytotoxicity and cytokine production by bovine alveolar macrophages challenged with wild type and leukotoxin-deficient mannheimia haemolytica.leukotoxin (lkt) is a virulence factor for mannheimia haemolytica. in this study, bovine alveolar macrophages (bams) were challenged with wild type (wt) and lkt deficient (lkt(-)) m. haemolytica at a concentration of 1 bacterium/bam and the cytokine response was quantified by elisa and real-time reverse transcriptase-pcr. significant increases in protein concentrations of tumor necrosis factor (tnf)-α and interleukin (il)-10 were observed in supernatants obtained from bams challenged with the lk ...201120542456
mannheimia haemolytica: bacterial-host interactions in bovine pneumonia.mannheimia haemolytica serotype s1 is considered the predominant cause of bovine pneumonic pasteurellosis, or shipping fever. various virulence factors allow m haemolytica to colonize the lungs and establish infection. these virulence factors include leukotoxin (lkt), lipopolysaccharide, adhesins, capsule, outer membrane proteins, and various proteases. the effects of lkt are species specific for ruminants, which stem from its unique interaction with the bovine β2 integrin receptor present on le ...201120685916
mannheimia haemolytica leukotoxin binds cyclophilin d on bovine neutrophil mitochondria.mannheimia haemolytica is an important member of the bovine respiratory disease (brd) complex that causes fibrinous and necrotizing pleuropneumonia in cattle. brd is characterized by abundant neutrophil infiltration into the alveoli and fibrin deposition. the most important virulence factor of m. haemolytica is its leukotoxin. previous research in our laboratory has shown that the leukotoxin is able to enter into and traffic to the mitochondria of a bovine lymphoblastoid cell line (bl-3). in thi ...201121220005
domestic sheep (ovis aries) pasteurellaceae isolates from diagnostic submissions to the caine veterinary teaching center (1990-2004).a retrospective study of pasteurellaceae isolated from domestic sheep (ovis aries) was conducted. the aim was to identify pasteurellaceae present in animals that were clinically healthy and others with evidence of respiratory disease. the bacteria had been isolated from samples submitted to the university of idaho caine veterinary teaching center as part of disease diagnostic testing. the 844 isolates identified mainly three species of pasteurellaceae: mannheimia haemolytica, pasteurella multoci ...201121345625
a novel erm monomethyltransferase in antibiotic-resistant isolates of mannheimia haemolytica and pasteurella multocida.mannheimia haemolytica and pasteurella multocida are aetiological agents commonly associated with respiratory tract infections in cattle. recent isolates of these pathogens have been shown to be resistant to macrolides and other ribosome-targeting antibiotics. direct analysis of the 23s rrnas by mass spectrometry revealed that nucleotide a2058 is monomethylated, consistent with a type i erm phenotype conferring macrolide-lincosamide resistance. the erm resistance determinant was identified by fu ...201121371136
crystal structure and immunogenicity of the class c acid phosphatase from pasteurella multocida.pasteurella multocida is a pathogen of veterinary and medical importance. here, we report the 1.85å resolution crystal structure of the class c acid phosphatase from this organism (denoted rpmccap). the structure shows that rpmccap exhibits the same haloacid dehalogenase fold and dimeric assembly as the class c enzyme from haemophilus influenzae. formation of the dimer in solution is demonstrated using analytical ultracentrifugation. the active site is devoid of a magnesium ion due to the presen ...201121371420
co-expression of ovine lps receptor cd14 with mannheimia haemolytica leukotoxin receptor lfa-1 or mac-1 does not enhance leukotoxin-induced cytotoxicity.leukotoxin (lkt) and lps are the major virulence determinants of mannheimia haemolytica that contribute to the pathogenesis of bovine and ovine pneumonic pasteurellosis. we have previously identified bovine and ovine cd18 as the functional receptor for lkt. lps complexes with lkt resulting in increased thermal stability and enhanced cytotoxic activity of lkt. cellular recognition of lps involves several different molecules including cd14. we hypothesized that expression of ovine cd14 together wi ...201121420740
demonstration of the metaphylactic use of gamithromycin against bacterial pathogens associated with bovine respiratory disease in a multicentre farm trial.on five commercial cattle rearing sites across europe, a total of 802 young cattle at high risk of developing bovine respiratory disease (brd) associated with the bacterial pathogens mannheimia haemolytica or pasteurella multocida and/or mycoplasma bovis were enrolled into a multicentre, controlled field trial. half were treated with a single dose of gamithromycin at 6 mg/kg bodyweight by subcutaneous injection and half received an injection of a saline placebo as the control. all animals were o ...201121493573
bacterial ghosts as antigen and drug delivery system for ocular surface diseases: effective internalization of bacterial ghosts by human conjunctival epithelial cells.the purpose of the presented investigation was to examine the efficiency of the novel carrier system bacterial ghosts (bgs), which are empty bacterial cell envelopes of gram-negative bacteria to target human conjunctival epithelial cells, as well as to test the endocytic capacity of conjunctival cells after co-incubation with bgs generated from different bacterial species, and to foreclose potential cytotoxic effects caused by bgs. the efficiency of conjunctival cells to internalize bgs was inve ...201121501636
the role of mannheimia species in ovine mastitis.mannheimia haemolytica is known to be an important cause of intramammary infection in sheep. it usually causes severe clinical mastitis, followed by toxaemia and gangrenous necrosis of the udder. however there are limited data available on the epidemiology and pathogenesis of mastitis associated with mannheimia species. these organisms can be more significant as a cause of mastitis than staphylococcus aureus in some flocks. some data suggest the possibility of horizontal transmission of mannheim ...201121511411
sequence analysis of serotype-specific synthesis regions ii of haemophilus influenzae serotypes c and d: evidence for common ancestry of capsule synthesis in pasteurellaceae and neisseria meningitidis.sequencing of yet unknown haemophilus influenzae serotype c (hic) and d (hid) capsule synthesis regions ii revealed four (ccs1-4) and five (dcs1-5) open reading frames, respectively. the inferred gene functions were in line with capsular polysaccharide structures. one or more proteins encoded by the hic capsule synthesis region ii showed similarity to actinobacillus pleuropneumoniae serotype 1 and actinobacillus suis k1 enzymes. orthologues to the complete operon were observed in actinobacillus ...201121513796
structural analyses of the core oligosaccharide from the lipopolysaccharide of bovine and ovine strains of mannheimia haemolytica serotype 2.previous structural studies in our laboratory on lipopolysaccharide derived core oligosaccharide had identified a conserved inner core structure in several strains of the veterinary pathogens mannheimia haemolytica, actinobacillus pleuropneumoniae and pasteurella multocida. in this study we describe the elucidation of the core oligosaccharide structure of two strains from m. haemolytica serotype 2. structural information was established by a combination of monosaccharide and methylation analyses ...201121601179
genomic characterization of haemophilus parasuis sh0165, a highly virulent strain of serovar 5 prevalent in china.haemophilus parasuis can be either a commensal bacterium of the porcine respiratory tract or an opportunistic pathogen causing glässer's disease, a severe systemic disease that has led to significant economical losses in the pig industry worldwide. we determined the complete genomic sequence of h. parasuis sh0165, a highly virulent strain of serovar 5, which was isolated from a hog pen in north china. the single circular chromosome was 2,269,156 base pairs in length and contained 2,031 protein-c ...201121611187
comparison of passively transferred antibodies in bighorn and domestic lambs reveals one factor in differential susceptibility of these species to mannheimia haemolytica-induced pneumonia.mannheimia haemolytica consistently causes fatal bronchopneumonia in bighorn sheep (bhs, ovis canadensis) under natural and experimental conditions. leukotoxin is the primary virulence factor of this organism. bhs are more susceptible to developing fatal pneumonia in comparison to the related species domestic sheep (ds, ovis aries). in bhs herds affected by pneumonia, lamb recruitment is severely impaired for years subsequent to an outbreak. we hypothesized that a lack of maternally derived anti ...201121613459
evaluation of protein expression in bovine bronchoalveolar fluid following challenge with mannheimia haemolytica.proteomics analysis of bovine bronchoalveolar fluid (baf) following induction of pneumonia with mannheimia haemolytica using nanoflow liquid chromatography coupled with tandem mass spectrometry (nanolc-ms/ms) resulted in the identification of 88 unique proteins. proteins detected in baf included antimicrobial peptides (amps), complement factors, acute phase proteins, protease inhibitors, and proteins involved in oxidation-reduction. notwithstanding biological variation, differences in relative p ...201121800424
a multivalent mannheimia/bibersteinia vaccine protects bighorn sheep against mannheimia haemolytica challenge.bighorn sheep (bhs) are more susceptible than domestic sheep (ds) to mannheimia haemolytica pneumonia. although both species carry m. haemolytica as a commensal bacterium in the nasopharynx, ds carry mostly leukotoxin (lkt)-positive strains while bhs carry lkt-negative strains. consequently, antibodies to surface antigens and lkt are present at much higher titers in ds, but lower in bhs. the objective of this study was to determine whether repeated immunization of bhs with multivalent mannheimia ...201121832104
incorporation of antigens from mannheimia haemolytica culture supernatant, and recombinant bovine c3d into iscom matrix using neutravidin-biotin interaction.the aim of this study was to incorporate antigens from mannheimia haemolytica culture supernatant, and an immune modulatory molecule, recombinant bovine c3d (rboc3d), into immune stimulating complexes (iscoms) using neutravidin-biotin interaction. biotinylated iscom matrix was generated using a commercial kit. the biotinylated iscom matrix was incubated with neutravidin and then centrifuged in a sucrose density gradient. the rboc3d was expressed as an in vivo biotinylated protein and with a c-my ...201121679244
prevalence of respiratory pathogens in diseased, non-vaccinated, routinely medicated veal calves.the prevalence of respiratory pathogens in diseased veal calves was determined in 24 respiratory disease outbreaks in 15 herds in belgium. bacteria were cultured from nasopharyngeal swabs and seroconversion against viruses and mycoplasma bovis was determined on paired sera. at the individual calf level, mycoplasma species, mannheimia haemolytica and pasteurella multocida, were isolated from 70.5 per cent, 21.5 per cent and 26.0 per cent of swabs, respectively. at the herd level, the presence of ...201121831999
cytokine expression by pulmonary leukocytes from calves challenged with wild-type and leukotoxin-deficient mannheimia haemolytica.the objective of this study was to assess the role of leukotoxin (lkt) in modulating the pulmonary cytokine response of calves challenged with mannheimia haemolytica. thirty-six calves, seronegative to lkt and m. haemolytica whole cell antigen were divided into three groups (i, ii and iii). calves in groups i and ii were challenged by the intra-bronchial route with 25ml of phosphate buffered saline (pbs) containing 0.44+ù10(9)cfu/ml of lkt deficient (lkt(-)) and 25ml of pbs containing 0.31+ù10(9 ...201121696986
combinations of macrolide resistance determinants in field isolates of mannheimia haemolytica and pasteurella multocida.respiratory tract infections in cattle are commonly associated with the bacterial pathogens mannheimia haemolytica and pasteurella multocida. these infections can generally be successfully treated in the field with one of several groups of antibiotics, including macrolides. a few recent isolates of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. the first class has type i macrolide, lincosamide, and streptogramin b antibiotic resis ...201121709086
molecular signatures (conserved indels) in protein sequences that are specific for the order pasteurellales and distinguish two of its main clades.the members of the order pasteurellales are currently distinguished primarily on the basis of their branching in the rrna trees and no convincing biochemical or molecular markers are known that distinguish them from all other bacteria. the genome sequences for 20 pasteurellaceae species/strains are now publicly available. we report here detailed analyses of protein sequences from these genomes to identify conserved signature indels (csis) that are specific for either all pasteurellales or its ma ...201121830122
relationship of in vitro minimum inhibitory concentrations of tilmicosin against mannheimia haemolytica and pasteurella multocida and in vivo tilmicosin treatment outcome among calves with signs of bovine respiratory disease.objective-to determine associations between in vitro minimum inhibitory concentrations (mics) of tilmicosin against mannheimia haemolytica and pasteurella multocida and in vivo tilmicosin treatment outcome among calves with clinical signs of bovine respiratory disease (brd). design-observational, retrospective, cohort study. animals-976 feeder calves with clinical signs of brd enrolled in 16 randomized clinical trials. procedures-records of clinical trials from october 26, 1996, to november 15, ...201121718206
investigating the candidacy of lipopolysaccharide-based glycoconjugates as vaccines to combat mannheimia haemolytica.inner core lipopolysaccharide (lps) has been shown to be conserved in the majority of veterinary strains from the species mannheimia haemolytica, actinobacillus pleuropneumoniae and pasteurella multocida and as such is being considered as a possible vaccine antigen. the proof-in-principle that a lps-based antigen could be considered as a vaccine candidate has been demonstrated from studies with monoclonal antibodies raised to the inner core lps of mannheimia haemolytica, which were shown to be b ...201121701793
defective bacterial clearance is responsible for the enhanced lung pathology characteristic of mannheimia haemolytica pneumonia in bighorn sheep.the molecular and cellular basis for the enhanced lung pathology and mortality caused by mannheimia haemolytica in bighorn sheep (bhs, ovis canadenesis), in comparison to domestic sheep (ds, ovis aries), is not clear. polymorphonuclear leukocytes (pmns) of bhs are four- to eight-fold more susceptible to m. haemolytica leukotoxin-induced cytolysis, which is likely to reduce the number of functional phagocytes in the lung. we hypothesized that enhanced lung pathology is due to defective clearance ...201121742446
Capsular polysaccharide vaccine for Group B Neisseria meningitidis, Escherichia coli K1, and Pasteurella haemolytica A2.We reviewed the literature that is the basis for our proposal that (2?8)-a-Neu5Ac conjugates will be safe and effective vaccines for Group B meningococci (GBMs), Escherichia coli K1, and Pasteurella haemolytica A2. Although (2?8)-a-Neu5Ac is a virulence factor and a protective antigen of these three pathogens, it is also a component of normal tissues (neural cell adhesion molecule). Natural, anti-(2?8)-a-Neu5Ac present in most adults, vaccine-induced antibodies, and even high levels of spontaneo ...201122025709
Immunogenicity of Mannheimia haemolytica Recombinant Outer Membrane Proteins Serotype 1-Specific Antigen, OmpA, OmpP2, and OmpD15.We previously identified Mannheimia haemolytica outer membrane proteins (OMPs) that may be important immunogens by using immunoproteomic analyses. Genes for serotype 1-specific antigen (SSA-1), OmpA, OmpP2, and OmpD15 were cloned and expressed, and recombinant proteins were purified. Objective 1 of this study was to demonstrate immunogenicity of the four recombinant OMPs in mice and cattle. Objective 2 was to determine if the addition of individual recombinant OMPs or combinations of them would ...201121976226
transmission of mannheimia haemolytica from domestic sheep (ovis aries) to bighorn sheep (ovis canadensis): unequivocal demonstration with green fluorescent protein-tagged organisms.previous studies demonstrated that bighorn sheep (ovis canadensis) died of pneumonia when commingled with domestic sheep (ovis aries) but did not conclusively prove that the responsible pathogens were transmitted from domestic to bighorn sheep. the objective of this study was to determine, unambiguously, whether mannheimia haemolytica can be transmitted from domestic to bighorn sheep when they commingle. four isolates of m. haemolytica were obtained from the pharynx of two of four domestic sheep ...201020688676
identification of putative two-component regulatory systems in the bovine pathogen mannheimia haemolytica a1, and preliminary characterization of the narq/p system.the complete genome sequence of the bovine pathogen mannheimia haemolytica a1 was analyzed by blast searches for the presence of two-component regulatory system proteins. five complete sets of putative two-component systems were identified, and the narq/p system was further investigated. in silico analysis of the narq and narp proteins showed features that are typical of the sensor and response regulator proteins. a narp knock-out mutant was constructed. the narp mutant has lost its ability to r ...201020722734
the synthesis of paleic acid, an antimicrobial agent effective against mannheimia and pasteurella, and its structurally related derivatives.a synthetic route to paleic acid 1, antimicrobial agent effective against mannheimia haemolytica and pasteurella multocida, has been established. the absolute configuration of the secondary hydroxyl group was controlled by a catalytic asymmetric alkylation of an aldehyde using a chiral titanium sulfonamide complex and the cis double bond was installed using a wittig reaction. this synthetic route was also applied to the preparation of structurally related analogs, which were used in structure-ac ...201020728353
mannheimia caviae sp. nov., isolated from epidemic conjunctivitis and otitis media in guinea pigs.strains t138021/75t, pg 19 and pg 20 (taxon 25 of bisgaard) all isolated from guinea pigs were characterized. strains t138021-75 t and pg20 showed identical 16s rrna gene sequences and were distantly related with the highest 16s rrna similarity of 98.6 % to the published strain p224, while the type strain of mannheimia glucosida and other strains of mannheimia glucosida demonstrated 97.8% similarity, while the type strain of mannheimia varigena showed 97.3% 16s rrna similarity, whereas all other ...201020729306
mannheimia haemolytica and its leukotoxin cause neutrophil extracellular trap formation by bovine neutrophils.mannheimia haemolytica is an important member of the bovine respiratory disease complex, which is characterized by abundant neutrophil infiltration into the alveoli and fibrin deposition. recently several authors have reported that human neutrophils release neutrophil extracellular traps (nets), which are protein-studded dna matrices capable of trapping and killing pathogens. here, we demonstrate that the leukotoxin (lkt) of m. haemolytica causes net formation by bovine neutrophils in a cd18-dep ...201020823211
localization and functional characterization of pulmonary bovine odorant-binding protein.bovine odorant-binding protein (obp) may function in olfaction and defense against oxidative injury, but its role in inflammation and defense against bacterial infection has not been investigated. expression of obp was discovered in the bovine lung and found to undergo changes in abundance during glucocorticoid administration and stress. obp was localized to nasal, tracheal, and bronchial mucosal glands with immunohistochemistry, with faint expression in airway surface epithelium and none in bro ...201020826843
transmission of mannheimia haemolytica from the tonsils of lambs to the teat of ewes during sucking.objective of the work was to study whether mannheimia haemolytica may be transmitted from the mouth of the lambs into the teat of the dam during sucking. we compared bacterial populations within the teat duct and milk of ewes immediately before and immediately after sucking by the lambs. tonsils of lambs of the ewes were swabbed. m. haemolytica strain dag21t recovered from a teat duct of a ewe was compared to strain dag21r recovered from the tonsils of her lamb by using 16s rrna sequencing. we u ...201020863634
evidence for a common gene pool and frequent recombinational exchange of the tbpba operon in mannheimia haemolytica, mannheimia glucosida and bibersteinia trehalosi.the tbpba operon was sequenced in 42 representative isolates of mannheimia haemolytica (32), mannheimia glucosida (6) and bibersteinia trehalosi (4). a total of 27 tbpb and 20 tbpa alleles were identified whilst the tbpba operon was represented by 28 unique alleles that could be assigned to seven classes. there were 1566 (34.8% variation) polymorphic nucleotide sites and 482 (32.1% variation) variable inferred amino acid positions among the 42 tbpba sequences. the tbpba operons of serotype a2 m. ...201020884693
a three-way comparative genomic analysis of mannheimia haemolytica isolates.mannhemia haemolytica is a gram-negative bacterium and the principal etiological agent associated with bovine respiratory disease complex. they transform from a benign commensal to a deadly pathogen, during stress such as viral infection and transportation to feedlots and cause acute pleuropneumonia commonly known as shipping fever. the u.s beef industry alone loses more than one billion dollars annually due to shipping fever. despite its enormous economic importance there are no specific and ac ...201020920355
ornithobacterium rhinotracheale north american field isolates express a hemolysin-like protein.ornithobacterium rhinotracheale is a gram-negative bacterium responsible for the sporadic outbreaks of airsacculitis in poultry, accounting for millions of dollars in losses to the poultry industry annually. although the organism was originally classified as non-beta-hemolytic, recent north american field isolates of o. rhinotracheale obtained from pneumonic lungs and air sacs indicated hemolytic activity on blood agar plates upon extended incubation for 48 hr at room temperature in air after in ...201020945779
anti-inflammatory benefits of antibiotic-induced neutrophil apoptosis: tulathromycin induces caspase-3-dependent neutrophil programmed cell death and inhibits nf-kappab signaling and cxcl8 transcription.clearance of apoptotic neutrophils is a central feature of the resolution of inflammation. findings indicate that immuno-modulation and induction of neutrophil apoptosis by macrolide antibiotics generate anti-inflammatory benefits via mechanisms that remain obscure. tulathromycin (tul), a new antimicrobial agent for bovine respiratory disease, offers superior clinical efficacy for reasons not fully understood. the aim of this study was to identify the immuno-modulating effects of tulathromycin a ...201020956586
a bighorn sheep die-off in southern colorado involving a pasteurellaceae strain that may have originated from syntopic cattle.we investigated a pasteurellosis epizootic in free-ranging bighorn sheep (ovis canadensis) wherein a pasteurellaceae strain carried by syntopic cattle (bos taurus) under severe winter conditions appeared to contribute to pneumonia in affected bighorns. twenty-one moribund or dead bighorn sheep were found on the "fossil ridge" herd's winter range, colorado, usa, between 13 december 2007 and 29 february 2008. eight carcasses examined showed gross or microscopic evidence of acute to subacute fibrin ...201020966277
determination of the duration of antibacterial efficacy following administration of gamithromycin using a bovine mannheimia haemolytica challenge model.the antibacterial efficacy of gamithromycin administered once 1, 5, or 10 days prior to a challenge infection with mannheimia haemolytica serotype a1 was evaluated. forty calves were randomly allocated on day -11, restricted by body weight, to one of three treatment groups given gamithromycin at 6 mg/kg of body weight 10, 5, or 1 days before challenge or to an untreated control group. m. haemolytica a1 challenge infections were induced on day 0 by depositing 7.4 × 10(7) cfu at the bifurcation of ...201021078926
deadly pneumonia traced to domestic sheep. 201021090151
pharmacokinetic and pharmacodynamic modelling of marbofloxacin administered alone and in combination with tolfenamic acid in calves.sidhu, p. k., landoni, m. f., aliabadi, m. h. s., toutain, p. l., lees, p. pharmacokinetic and pharmacodynamic modelling of marbofloxacin administered alone and in combination with tolfenamic acid in calves. j. vet. pharmacol. therap. doi: 10.1111/j.1365-2885.2010.01247.x. in a four-period, cross-over study, the fluoroquinolone antibacterial drug marbofloxacin (mb) was administered to calves, alone and in combination with the nonsteroidal anti-inflammatory drug tolfenamic acid (ta). both drugs w ...201021091727
genetic characterization and antimicrobial susceptibility of mannheimia haemolytica isolated from the nasopharynx of feedlot cattle.a surveillance study was undertaken to examine the population dynamics and antimicrobial resistance of mannheimia haemolytica isolated from feedlot cattle. a total of 416 isolates were collected from the nasopharynx either upon entry or exit from two feedlots in southern alberta, canada. isolates were serotyped, characterized by pulsed-field gel electrophoresis and tested for susceptibility to ten antimicrobial agents via disk diffusion. resistant isolates were screened by pcr for select antimic ...201021146332
rumen temperature change monitored with remote rumen temperature boluses after challenges with bovine viral diarrhea virus and mannheimia haemolytica.remote rumen temperature monitoring is a potential method for early disease detection in beef cattle. this experiment was conducted to determine if remotely monitored rumen temperature boluses could detect a temperature change in steers exposed to bovine viral diarrhea virus (bvdv) and challenged with a common bovine respiratory disease pathogen, mannheimia haemolytica (mh). twenty-four angus crossbred steers (bw = 313 ± 31 kg) were allotted to 1 of 4 treatments: 1) no challenge (control); 2) ch ...201021169514
pharmacokinetics of gamithromycin in cattle with comparison of plasma and lung tissue concentrations and plasma antibacterial activity.the pharmacokinetics (pk) and dose proportionality of gamithromycin (zactran), a novel azalide, after a single intravenous (i.v.) dose of 3 mg/kg or subcutaneous (s.c.) injection at 3, 6 and 9 mg/kg body weight were studied in 13 male castrate and 13 female angus cattle. following i.v. administration, the mean area under the curve extrapolated to infinity (auc(inf)) was 4.28 +/- 0.536 microgxh/ml, and mean elimination half-life (t(1/2)) was 44.9 +/- 4.67 h, with a large volume of distribution (v ...201020557439
molecular cloning, characterization and in vitro expression of serpin b1 of bighorn sheep (ovis canadensis) and domestic sheep (ovis aries), and comparison with that of other species.mannheimia haemolytica infection results in enhanced pmn-mediated tissue damage in the lungs of bighorn sheep (bhs) compared to that of domestic sheep (ds). serpin b1 is an inhibitor of pmn-derived serine proteases. it prevents lung tissue injury by inhibiting the serine proteases released as a result of pmn lysis and degranulation. it is conceivable that pmns of bhs exhibit decreased quantity and/or activity of serpin b1 which results in enhanced tissue injury and decreased bacterial clearance ...201020591503
experimental infection of peste des petit ruminant virus and mannheimia haemolytica a2 in goats: immunolocalisation of mannheimia haemolytica antigens.nigerian strain of peste des petit ruminant (ppr) virus and mannheimia haemolytica (mh) biotype a serotype 2, was used successfully to reproduce a concurrent disease in west african dwarf goats. the development of the various pathological features were studied at regular intervals following infection. the acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together wit ...201020617380
bacterial pathogens of the bovine respiratory disease complex.pneumonia caused by the bacterial pathogens discussed in this article is the most significant cause of morbidity and mortality of the brdc. most of these infectious bacteria are not capable of inducing significant disease without the presence of other predisposing environmental factors, physiologic stressors, or concurrent infections. mannheimia haemolytica is the most common and serious of these bacterial agents and is therefore also the most highly characterized. there are other important bact ...201020619191
molecular cloning of interleukin-1β, interleukin-8, and tumor necrosis factor-α of bighorn sheep (ovis canadensis) and comparison with those of other species.the susceptibility to, and pathology induced by, mannheimia haemolytica infection in bighorn sheep (bhs) and domestic sheep (ds) are distinctly different. bighorn sheep are particularly susceptible to pneumonia caused by m. haemolytica, and the pneumonic lesions in infected bhs are more severe than those in ds. the molecular basis for this disparity has not been elucidated. proinflammatory cytokines have been implicated in the pathogenesis of multiple lung diseases of humans and animals. it is p ...201020655598
paleic acid, a fatty acid from paenibacillus sp.: taxonomy, fermentation, isolation, structure determination, and anti-mannheimia and -pasteurella activity.paleic acid (1), an antibiotic, was obtained from a fermentation broth of paenibacillus sp. bmk771-af3. the compound is a fatty acid (9z,16r)-16-hydroxy-9-octadecenoic acid ((r)-16-hydroxyoleic acid), whose isolation required protection of its polar functional groups. mosher esters of paleic acid yielded information on the absolute configuration of secondary alcohol, and well-resolved (1)h nmr peaks around the double bond suggested that olefin adopted a z geometry. paleic acid showed potent anti ...201020664607
genome sequences of mannheimia haemolytica serotype a2: ovine and bovine isolates.this report describes the genome sequences of mannheimia haemolytica serotype a2 isolated from pneumonic lungs of two different ruminant species, one from ovis aries, designated ovine (o), and the other from bos taurus, designated bovine (b).201019966002
distribution of ceftiofur into mannheimia haemolytica-infected tissue chambers and lung after subcutaneous administration of ceftiofur crystalline free acid sterile suspension.the objective of this study was to evaluate the penetration of ceftiofur- and desfuroylceftiofur-related metabolites (dca) into sterile and infected tissue chambers, lung tissue and disposition of dca in plasma across four different sacrifice days postdosing. twelve healthy calves were utilized following implantation with tissue chambers in the paralumbar fossa. tissue chambers in each calf were randomly inoculated with either mannheimia haemolytica or sterile pbs. all calves were dosed with cef ...201020444038
mycoplasma ovipneumoniae can predispose bighorn sheep to fatal mannheimia haemolytica pneumonia.mycoplasma ovipneumoniae has been isolated from the lungs of pneumonic bighorn sheep (bhs). however experimental reproduction of fatal pneumonia in bhs with m. ovipneumoniae was not successful. therefore the specific role, if any, of m. ovipneumoniae in bhs pneumonia is unclear. the objective of this study was to determine whether m. ovipneumoniae alone causes fatal pneumonia in bhs, or predisposes them to infection by mannheimia haemolytica. we chose m. haemolytica for this study because of its ...201020466492
differential expression of interleukin-8 by polymorphonuclear leukocytes of two closely related species, ovis canadensis and ovis aries, in response to mannheimia haemolytica infection.the pneumonic lesions and mortality caused by mannheimia haemolytica in bighorn sheep (bhs; ovis canadensis) are more severe than those in the related species, domestic sheep (ds; ovis aries), under both natural and experimental conditions. leukotoxin (lkt) and lipopolysaccharide (lps) are the most important virulence factors of this organism. one hallmark of pathogenesis of pneumonia is the influx of polymorphonuclear leukocytes (pmns) into the lungs. lkt-induced cytolysis of pmns results in th ...201020515932
development of enzyme-linked immunosorbent assay for bovine surfactant protein d in bronchoalveolar lavage fluid.surfactant protein d (sp-d) is a pattern recognition molecule that has an important role in pulmonary host defense. in this study, we developed an enzyme-linked immunosorbent assay (elisa) for bovine sp-d and determined the concentration of sp-d in bronchoalveolar lavage fluid (balf) from calves. bovine sp-d was purified from balf using a mannose-shepharose 6b column. the obtained 44 kda protein was identified as bovine sp-d by n-terminal amino acid sequence analysis and sds-page analysis. the p ...201020526045
the induction of lymphoid follicle-like structures in the ovine teat duct following experimental infection with mannheimia haemolytica.the objectives of this study were to investigate the early stages of experimental infection of the ovine mammary gland with mannheimia haemolytica and to identify the lymphocyte subsets accumulating at the teat duct. m. haemolytica was inoculated into one teat of each of 25 ewes and clinical, bacteriological, cytological, haematological, physicochemical, gross pathological, histopathological and immunohistochemical examinations were carried out. clinical signs of inflammation were evident by 8 h ...201019268613
pharmacokinetic and pharmacodynamic modelling of marbofloxacin administered alone and in combination with tolfenamic acid in goats.in a four-period cross-over study, the fluoroquinolone antibacterial drug marbofloxacin (mb) was administered to goats intramuscularly (im) at a dose rate of 2 mg/kg, both alone and in combination with the non-steroidal anti-inflammatory drug tolfenamic acid (ta), also administered im at a dose rate of 2 mg/kg. using a tissue cage model of inflammation, based on the irritant actions of carrageenan, the pharmacokinetics (pk) of mb and mb in combination with ta were determined. mb mean values of a ...201019299172
atypical non-progressive pneumonia in goats.an outbreak of severe respiratory disease in a goat herd was associated with mycoplasma ovipneumoniae, mycoplasma arginini, mannheimia haemolytica and pasteurella multocida with mortality rates exceeding 20% in kids. post mortem features in affected kids included severe pleuropneumonia, lung consolidation, large quantities of pleural fluid and pericarditis. this is the first report of atypical proliferative pneumonia in goats in portugal.201019596209
pk-pd integration and modeling of marbofloxacin in sheep.the fluoroquinolone antimicrobial drug, marbofloxacin, was administered intravenously (iv) and intramuscularly (im) to sheep at a dose rate of 2 mg kg(-1) in a 2-period cross-over study. using a tissue cage model of inflammation, the pharmacokinetic properties of marbofloxacin were established for serum, inflamed tissue cage fluid (exudate) and non-inflamed tissue cage fluid (transudate). for serum, after iv dosing, mean values for pharmacokinetic parameters were: clearance 0.48 l kg(-1) h(-1); ...201019523661
expression and activity of n-myristoyltransferase in lung inflammation of cattle and its role in neutrophil apoptosis.n-myristoyltransferase (nmt) attaches a 14 carbon fatty acid, myristic acid, to the n-terminal glycine residue of proteins. nmt exists in two isoforms nmt1 and nmt2. myristoylated proteins play critical roles in protein-protein interactions, cell signaling and oncogenesis. although elevated expression of nmt1 has been described in colorectal carcinoma, its expression and roles in normal and inflamed lungs of the cattle are unknown. therefore, we investigated the expression and activity of nmt in ...201019796608
orbus hercynius gen. nov., sp. nov., isolated from faeces of wild boar, is most closely related to members of the orders 'enterobacteriales' and pasteurellales.a novel gammaproteobacterium, strain cn3(t), was isolated from the faeces of wild boar. strain cn3(t) was facultatively anaerobic and appeared coccoid or rod-shaped. the partial 16s rrna gene sequence determined for strain cn3(t) suggested a distant relationship with members of the orders 'enterobacteriales' and pasteurellales. the gene sequence showed highest similarity (90.3 %) with obesumbacterium proteus dsm 2777(t), a member of the family enterobacteriaceae. the closest relatives outside th ...201020023064
bibersteinia trehalosi inhibits the growth of mannheimia haemolytica by a proximity-dependent mechanism.mannheimia (pasteurella) haemolytica is the only pathogen that consistently causes severe bronchopneumonia and rapid death of bighorn sheep (bhs; ovis canadensis) under experimental conditions. paradoxically, bibersteinia (pasteurella) trehalosi and pasteurella multocida have been isolated from bhs pneumonic lungs much more frequently than m. haemolytica. these observations suggest that there may be an interaction between these bacteria, and we hypothesized that b. trehalosi overgrows or otherwi ...201020038698
ovis aries cr4 is involved in mannheimia haemolytica leukotoxin-induced cytotoxicity.pneumonia caused by mannheimia haemolytica is an important disease of domestic sheep (ds, ovis aries) and cattle (bo). m. haemolytica is a normal commensal of the upper respiratory tract in ruminants, but during stress and viral infection it breaches the host innate mucosal defense and descents into lungs causing fibrinous pleuropneumonia. leukotoxin (lkt) produced by m. haemolytica is cytolytic to all subsets of ruminant leukocytes. earlier, we and others have shown that ds and bo lfa-1 (cd11a/ ...201020060597
a single vaccination with an inactivated bovine respiratory syncytial virus vaccine primes the cellular immune response in calves with maternal antibody.the efficacy of a single dose of an inactivated bovine respiratory syncytial virus (brsv)--parainfluenaza type 3 (pi3)--mannheimia haemolytica (mh) combination vaccine, in calves positive for maternal antibodies, was established in a brsv infection study.201020064236
n-terminal region of mannheimia haemolytica leukotoxin serves as a mitochondrial targeting signal in mammalian cells.mannheimia haemolytica leukotoxin (lkta) is a member of the rtx toxin family that specifically kills ruminant leukocytes. previous studies have shown that lkta induces apoptosis in susceptible cells via a caspase-9-dependent pathway that involves binding of lkta to mitochondria. in this study, using the bioinformatics tool mitoprot ii we identified an n-terminal amino acid sequence of lkta that represents a mitochondrial targeting signal (mts). we show that expression of this sequence, as a gfp ...201020109159
bovine pasteurellosis and other bacterial infections of the respiratory tract.despite technological, biologic, and pharmacologic advances the bacterial component of the bovine respiratory disease (brd) complex continues to have a major adverse effect on the health and wellbeing of stocker and feeder cattle. overlooked in this disappointing assessment is evaluation of the effects that working with younger, lighter-weight cattle have on managing the bacterial component of the brd complex. most problems associated with brd come from cattle taken from and comingled with cattl ...201020117542
comparison of repetitive pcr and pulsed-field gel electrophoresis for the genotyping of mannheimia haemolytica.mannheimia haemolytica is an opportunistic pathogen that can cause fibrinonecrotic pneumonia in cattle and is the main bacterial agent implicated in bovine respiratory disease-complex (brd). despite its economic importance to the cattle industry, few studies have characterized the genetic nature of m. haemolytica and none have genotyped isolates from feedlots. identifying and monitoring genetic variants of m. haemolytica is important to understanding the etiology of brd in cattle. we investigate ...201020122972
molecular classification and its impact on diagnostics and understanding the phylogeny and epidemiology of selected members of pasteurellaceae of veterinary importance.in this paper we briefly report recent taxonomic changes that have taken place within the bacterial family pasteurellaceae as a result of molecular investigations. we address the complexity and diagnostic possibilities and outline the current knowledge on the population structure these investigations have generated. in addition, we discuss future possibilities to improve basic understanding of genetic diversity at population level, possible host adaptation and stability of clones associated with ...201020135907
effects of exposure to calves persistently infected with bovine viral diarrhea virus type 1b and mannheimia haemolytica challenge on animal performance, nitrogen balance, and visceral organ mass in beef steers.bovine viral diarrhea viruses (bvdv) have been isolated alone or in combination with other viral and bacterial pathogens in animals diagnosed with bovine respiratory disease (brd), a disease causing major economic loss to the feedlot industry. the objective of this experiment was to determine the effects of mannheimia haemolytica challenge after short-term exposure (72 h) to bovine viral diarrhea virus type 1b (bvdv1b) persistently infected (pi) calves on performance, n balance, and organ mass i ...201020154160
effects of exposure to calves persistently infected with bovine viral diarrhea virus type 1b and subsequent infection with mannheima haemolytica on clinical signs and immune variables: model for bovine respiratory disease via viral and bacterial interaction.the objective was to determine effects of an intratracheal mannheimia haemolytica challenge after 72-h exposure to bovine viral diarrhea virus type 1b (bvdv1b) persistently infected (pi) calves on serum antibody production, white blood cell count (wbc), cytokine concentrations, and blood gases in feedlot steers. twenty-four steers (initial bw = 314 +/- 31 kg) were randomly allocated to 1 of 4 treatments (6 steers/treatment) arranged as a 2 x 2 factorial. treatments were 1) steers not exposed to ...201020154164
molecular cloning of cd18 of bison, deer and elk, and comparison with that of other ruminants and non-ruminants.pneumonia caused by mannheimia haemolytica is an important disease of cattle, domestic sheep, bighorn sheep and goats. leukotoxin (lkt) produced by m. haemolytica is cytolytic to all leukocyte subsets of these species. lkt utilizes cd18, the beta subunit of beta(2)-integrins, as its functional receptor on leukocytes of these species. cytotoxicity assays revealed that leukocytes from bison, deer, and elk are also susceptible to lkt-induced cytolysis. the availability of cdna encoding cd18 of biso ...201020176404
serial evaluation of physiologic, pathological, and behavioral changes related to disease progression of experimentally induced mannheimia haemolytica pneumonia in postweaned calves.to determine the usefulness of physiologic, behavioral, and pathological changes as objective indicators of early respiratory disease in calves with mannheimia haemolytica pneumonia.201020187839
immunoproteomic analyses of outer membrane proteins of mannheimia haemolytica and identification of potential vaccine candidates.immunoproteomic analyses were used to characterize the outer membrane proteome of mannheimia haemolytica, formerly pasteurella haemolytica, serotype 1, and determine potential vaccine candidate proteins. 2-de of m. haemolytica outer membranes was followed by immunoblot analyses using naïve and convalescent bovine sera. proteins were identified using maldi-tof and lc-ms/ms. spectral data was used to mine m. haemolytica protein database and 132 immunoreactive proteins were identified. bioinformati ...201020336679
pharmacodynamics of amoxicillin against mannheimia haemolytica and pasteurella multocida and pharmacokinetic/pharmacodynamic (pk/pd) correlation in sheep.silicone-made tissue cages were implanted in sheep. blood serum (sbs) and tissue cage fluid (tcf) samples were collected after amoxicillin intravenous and intramuscular administrations, at the dose of 15 mg/kg. amoxicillin pharmacodynamics were studied in an artificial culture medium, sbs and tcf with use of a mannheimia haemolytica and a pasteurella multocida strain. a concentration-independent antimicrobial activity of amoxicillin was confirmed for levels higher than 0.79-1.75×mic. this result ...201020363488
an ecologic study comparing distribution of pasteurella trehalosi and mannheimia haemolytica between sierra nevada bighorn sheep, white mountain bighorn sheep, and domestic sheep.the prevalence and phenotypic variability of pasteurella and mannheimia isolates from sierra nevada bighorn sheep (ovis canadensis sierrae), white mountain bighorn sheep (ovis canadensis nelsoni), and domestic sheep (ovis aries) from california, usa, were compared. the white mountain bighorn sheep population had a recent history of pneumonia-associated mortality, whereas the sierra nevada bighorn sheep population had no recent history of pneumonia-associated mortality. the domestic sheep flocks ...200919901369
enterobacteriaceae and pseudomonadaceae on the dorsum of the human tongue.the aim of this study was to correlate the presence of enterobacteriaceae, pseudomonadaceae, moraxellaceae and xanthomonadaceae on the posterior dorsum of the human tongue with the presence of tongue coating, gender, age, smoking habit and denture use.200919936511
lung pathology and infectious agents in fatal feedlot pneumonias and relationship with mortality, disease onset, and treatments.this study charted 237 fatal cases of bovine respiratory disease (brd) observed from may 2002 to may 2003 in a single oklahoma feed yard. postmortem lung samples were used for agent identification and histopathology. late in the study, 94 skin samples (ear notches) were tested for bovine viral diarrhea virus (bvdv) by immunohistochemistry (ihc). bovine respiratory disease morbidity was 14.7%, and the mortality rate of all causes was 1.3%, with more than half (53.8%) attributed to brd (0.7% total ...200919564494
intranasal vaccination of calves with mannheimia haemolytica chimeric protein containing the major surface epitope of outer membrane lipoprotein plpe, the neutralizing epitope of leukotoxin, and cholera toxin subunit b.this study was done to determine if intranasal vaccination of weaned beef calves with a chimeric protein containing the immunodominant surface epitope of mannheimia haemolytica plpe (r2) and the neutralizing epitope of leukotoxin (nlkt) covalently linked to truncated cholera toxin (ct) subunit b (ctb) could stimulate secretory and systemic antibodies against m. haemolytica while enhancing resistance of cattle against m. haemolytica intrabronchial challenge. sixteen weaned beef calves were intran ...200919581005
pharmacokinetics and pharmacokinetic/pharmacodynamic integration of orbifloxacin in korean hanwoo cattle.the pharmacokinetics and pharmacodynamics of orbifloxacin were studied in six clinically healthy hanwoo cows after intravenous (i.v.) and intramuscular (i.m.) administration at a dose of 3 mg/kg. orbifloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. steady-state volume of distribution and clearance of orbifloxacin after i.v. administration were 0.92 l/kg and 0.24 l/h x kg, respectively. following i.m. administration, a slow and complet ...200919646085
new plasmid tools for genetic analysis of actinobacillus pleuropneumoniae and other pasteurellaceae.we have generated a set of plasmids, based on the mobilizable shuttle vector pmidg100, which can be used as tools for genetic manipulation of actinobacillus pleuropneumoniae and other members of the pasteurellaceae. a tandem reporter plasmid, pmc-tandem, carrying promoterless xyle and gfpmut3 genes downstream of a multiple-cloning site (mcs), can be used for identification of transcriptional regulators and conditions which favor gene expression from different cloned promoters. the ability to det ...200919666733
exposure to pathogens and incidence of respiratory disease in young bulls on their arrival at fattening operations in france.the incidence of clinical respiratory disease in 698 young beef bulls kept in 68 pens, and their exposure to respiratory pathogens after their arrival at 51 fattening operations in western france were assessed. antibodies against bovine respiratory syncytial virus (brsv), bovine herpesvirus type 1 (bhv-1), mannheimia haemolytica and mycoplasma bovis were measured by elisa. the incidence risk of respiratory disease was 18.5 per cent during the first six weeks. cases occurred in 37 of the 68 pens, ...200919684344
intact signal peptide of cd18, the beta-subunit of beta2-integrins, renders ruminants susceptible to mannheimia haemolytica leukotoxin.signal peptides of membrane proteins are cleaved by endoplasmic reticulum-resident signal peptidase, and thus, are not present on mature membrane proteins. here, we report that, contrary to the paradigm, the signal peptide of ruminant cd18, the beta-subunit of beta(2)-integrins, is not cleaved. intriguingly, the intact signal peptide of cd18 is responsible for the susceptibility of ruminant leukocytes to mannheimia (pasteurella) haemolytica leukotoxin (lkt). inhibition of lkt-induced cytolysis o ...200919706410
analysis of a collagen-binding trimeric autotransporter adhesin from mannheimia haemolytica a1.a locus that codes for a high-molecular-weight adhesin was previously isolated from mannheimia haemolytica a1. in this study, we showed that this locus, named ahs, codes for two proteins (ahsa and ahsb) that exhibit characteristics of a trimeric autotransporter adhesin. sequence analysis of ahsa showed the presence of 21 collagen-binding motifs in the protein. collagen-binding assays showed that m. haemolytica a1 binds to collagen in a dose-dependent manner. this binding activity is trypsin sens ...200919796136
brief heat treatment increases cytotoxicity of mannheimia haemolytica leukotoxin in an lfa-1 independent manner.mannheimia haemolytica is an important respiratory pathogen in cattle. its predominant virulence factor is a leukotoxin (lkt) that is a member of the rtx family of exotoxins produced by a variety of gram negative bacteria. lkt binds to the cd18 chain of beta(2) integrins on bovine leukocytes, resulting in cell death. in this study, we show that brief heat treatment of native lkt (95 degrees c for 3 min) results in increased cytotoxicity for bl-3 (bovine lymphoblastoid) cells. similar heat treatm ...200919185607
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