Publications

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immunity of cattle following vaccination with a mannheimia haemolytica chimeric plpe-lkt (sac89) protein.we developed several chimeric plpe-leukotoxin (lkt) constructs containing the major epitope of mannheimia haemolytica outer membrane lipoprotein plpe (epitope r2) and the neutralizing epitope of m. haemolytica lkt (nlkt) [ayalew et al. mannheimia haemolytica chimeric protein vaccine composed of the major surface-exposed epitope of outer membrane lipoprotein plpe and the neutralizing epitope of leukotoxin. vaccine 2008;26(38):4955-61]. vaccination of mice with these plpe-lkt chimeric proteins sti ...200918834912
immunohistochemical detection of mannheimia (pasteurella) haemolytica antigens in goats with natural pneumonia.pneumonia is a leading cause of loss to ruminants throughout the world. mannheimia (pasteurella) haemolytica is one of the most important etiological agent of pneumonia in cattle, sheep, and goats. this study was carried out to determine the incidence of m.haemolytica antigens using immunohistochemistry labelling of formalin-fixed, paraffin-embedded tissues in pneumonic lungs of goats slaughtered at abattoir, and then to compare these immunohistochemistry results with the results of bacterial is ...200918972219
identification of mannheimia haemolytica adhesins involved in binding to bovine bronchial epithelial cells.mannheimia haemolytica, a commensal organism of the upper respiratory tract in cattle, is the principal bacterial pathogen associated with the bovine respiratory disease complex. adherence to the respiratory mucosa is a crucial event in its pathogenesis. however, the bacterial components that contribute to this process are not fully characterized. in this study, we demonstrated that m. haemolytica adhered to bovine bronchial epithelial cells (bbec) in vitro and that adherence was inhibited by an ...200918981250
challenges in mucosal vaccination of cattle.recognition of the mucosal portal of entry for many infectious diseases and of the relevance of mucosal immune response to protection has encouraged the development of vaccines administered by mucosal routes, principally oral and intranasal, for stimulation of intestinal and nasopharyngeal lymphoid tissues respectively. the oral route is problematic in cattle and other ruminants where antigen degradation in the rumen is likely, prior to transit to the intestine. on the other hand, rumination can ...200919046777
bovine respiratory disease research (1983-2009).bovine respiratory disease (brd) research has provided significant understanding of the disease over the past 26 years. modern research tools that have been used include monoclonal antibodies, genomics, polymerase chain reaction, immunohistochemistry (ihc), dna vaccines and viral vectors coding for immunogens. emerging/reemerging viruses and new antigenic strains of viruses and bacteria have been identified. methods of detection and the role for cattle persistently infected bovine viral diarrhea ...200920003649
host response to bovine respiratory pathogens.bovine respiratory disease (brd) involves complex interactions amongst viral and bacterial pathogens that can lead to intense pulmonary inflammation (fibrinous pleuropneumonia). viral infection greatly increases the susceptibility of cattle to secondary infection of the lung with bacterial pathogens like mannheimia haemolytica and histophilus somni. the underlying reason for this viral/bacterial synergism, and the manner in which cattle respond to the virulence strategies of the bacterial pathog ...200920003650
update on bacterial pathogenesis in brd.mannheimia haemolytica, pasteurella multocida, histophilus somni, mycoplasma bovis and arcanobacterium pyogenes are all frequently implicated in bovine respiratory disease (brd). m. haemolytica is considered the most important of the group. these bacteria are commensals in the nasopharynx and establish infection in the lungs of cattle that are subjected to a variety of stresses. factors that permit adherence to and proliferation in the lungs and factors that cause tissue destruction and inflamma ...200920003651
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
field efficacy of combination vaccines against bovine respiratory pathogens in calves.the efficacy of an inactivated bovine respiratory syncytial virus (brsv)--bovine parainfluenza type 3 (pi3)--mannheimia haemolytica (mh) combination vaccine was examined in two field studies. calves were vaccinated (i) with the inactivated vaccine, (ii) a modified live/killed viral combination vaccine, or (iii) left unvaccinated. the efficacy of the vaccines was judged by the (i) number of treated animals, (ii) number of individual antibiotic treatments per calf and (iii) mortality rates. after ...200819149103
in vitro activities of tulathromycin and ceftiofur combined with other antimicrobial agents using bovine pasteurella multocida and mannheimia haemolytica isolates.the purpose of this study was to determine the activities of two antibacterial agents used in the treatment of bovine respiratory infections-tulathromycin, a macrolide, and ceftiofur, a third-generation cephalosporin-alone, in combination with each other, and in combination with each of seven additional antibiotics (tilmicosin, florfenicol, enrofloxacin, danofloxacin, ampicillin, tetracycline, and penicillin g) against bovine pasteurella multocida (n = 60) and mannheimia haemolytica (n = 10) iso ...200819003782
safety and efficacy testing of a novel multivalent bovine bacterial respiratory vaccine composed of five bacterins and two immunogens.bovine bacterial respiratory diseases have been one of the most serious problems due to their high mortality and economic loss in calves. the vaccinations of bovine bacterial respiratory vaccines have been complex because of no multivalent vaccine. in this study, novel multivalent bovine bacterial respiratory vaccine (brv) was developed and tested for its safety and efficacy. brv was composed of two immunogens and five bacterins. these were leukotoxoid and bacterin of mannheimia haemolytica type ...200818840971
mannheimia haemolytica leukotoxin-induced cytolysis of caprine (capra hircus) leukocytes is mediated by the cd18 subunit of beta2-integrins.mannheimiosis is the major respiratory disease among some ruminants, whereas it is not pathogenic for other mammals, an observation that has been attributed to a specific interaction between mannheimia haemolytica leukotoxin (lkt) and bovine or ovine cd18 subunit of lymphocyte function-associated antigen-1 (lfa-1) and mac-1. we therefore hypothesized that lkt utilizes cd18 as its receptor on caprine leukocytes as well. we have transiently transfected the beta2-integrins-deficient k-562 cell line ...200818775487
[fatty acid composition of cells and lipopolysaccliarides of mannheimia haemolytica, mannheimia glucosida and bibersteinia trehalosi strains].the mannheimia haemolytica, mannheimia glucosida and bibersteinia trehalosi strains and the similar fatty acid composition of cells with domination of c(16:1) and c(16:0), which were in almost equal quantities, c(14:0 and c(18:1) + c(18:2). the fatty acid composition of lipopolysaccharides (lps) of the studied bacteria had no essential differences too. it was mainly represented by c(14:0) and 3-oh-c(14:0) which consisted of more than 80% of all lps fatty acids. c(12:0), c(16:1) and c(16:0) were ...200819351048
beta(2) integrin mac-1 is a receptor for mannheimia haemolytica leukotoxin on bovine and ovine leukocytes.pneumonia caused by mannheimia haemolytica is an important disease of cattle (bo), domestic sheep (ds, ovis aries) and bighorn sheep (bhs, ovis canadensis). leukotoxin (lkt) produced by m. haemolytica is cytolytic to all leukocyte subsets of these three species. although it is certain that cd18, the beta subunit of beta(2) integrins, mediates lkt-induced cytolysis of leukocytes, whether cd18 of all three beta(2) integrins, lfa-1 (cd11a/cd18), mac-1 (cd11b/cd18) and cr4 (cd11c/cd18), mediates lkt ...200818262657
kinetics of growth and leukotoxin production by mannheimia haemolytica in continuous culture.the growth and product formation kinetics of the bovine pathogen mannheimia (pasteurella) haemolytica strain ovi-1 in continuous culture were investigated. the leukotoxin (lkt) concentration and yield on biomass could substantially be enhanced by supplementation of a carbon-limited medium with an amino acid mixture or a mixture of cysteine and glutamine. acetic acid was a major product, increasing to 1.66 g l(-1) in carbon-limited chemostat culture at intermediate dilution rates and accounting f ...200818283506
a multiplex polymerase chain reaction assay for the identification of mannheimia haemolytica, mannheimia glucosida and mannheimia ruminalis.the objective of this study was to design a multiplex pcr assay to identify mannheimia haemolytica, mannheimia glucosida and mannheimia ruminalis. the multiplex pcr included primer sets hp, amplifying a dna region from an unknown hypothetical protein, lkt and lkt2, amplifying different regions of the leukotoxind gene, and 16s to amplify universal bacterial sequences of the 16s rrna gene. based on positive amplification, isolates were delineated as m. haemolytica (hp, lkt, 16s), m. glucosida (hp, ...200818308486
respiratory disease in lambs. 200818326850
epidemic pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep.a pneumonia epidemic reduced bighorn sheep (ovis canadensis) survival and recruitment during 1997-2000 in a population comprised of three interconnected wintering herds (kenosha mountains, sugarloaf mountain, twin eagles) that inhabited the kenosha and tarryall mountain ranges in central colorado, usa. the onset of this epidemic coincided temporally and spatially with the appearance of a single domestic sheep (ovis aires) on the sugarloaf mountain herd's winter range in december 1997. although o ...200818436671
expression of a modified mannheimia haemolytica gs60 outer membrane lipoprotein in transgenic alfalfa for the development of an edible vaccine against bovine pneumonic pasteurellosis.the gs60 antigen is one of the protective antigens of mannheimia haemolytica a1. gs60 contains conserved domains belonging to the lppc family of bacterial outer membrane lipoproteins. a high antibody titer to gs60 has been shown to be significantly correlated with resistance to pneumonic pasteurellosis. calves vaccinated with a commercial vaccine (presponse) and demonstrating protection against m. haemolytica a1 produced antibodies directed against gs60. alfalfa was chosen as the platform for an ...200818440084
an outbreak of chronic pneumonia and polyarthritis syndrome caused by mycoplasma bovis in feedlot bison (bison bison).mycoplasma bovis was identified by a specific lesion, conventional bacterial culture, immunohistochemistry, and polymerase chain reaction in 2 feedlot bison found dead with severe, chronic, caseonecrotic pneumonia; polyarthritis; and laryngitis. on microscopic examination, pulmonary lesions were characterized by prominent, well-defined areas of caseous necrosis and bronchiectasis. immunohistochemical analysis of lung exhibited staining in bronchiolar epithelium and in random areas of caseous nec ...200818460630
a comparison of 2 vaccination programs in feedlot calves at ultra-high risk of developing undifferentiated fever/bovine respiratory disease.the aim of this study was to compare 2 vaccination programs in feedlot calves at ultra-high risk of developing undifferentiated fever (uf)/bovine respiratory disease (brd). at feedlot arrival, 3882 calves were enrolled in the study and randomly allocated to 2 groups, which were housed by group in 12 pens. at the time of allocation, 1 group (mlv3-bt2) received a multivalent, modified-live viral vaccine containing infectious bovine rhinotracheitis virus (ibrv) and types i and ii bovine viral diarr ...200818512457
microbiological and histopathological findings in cases of fatal bovine respiratory disease of feedlot cattle in western canada.the aim of this study was to describe the microbiologic agents and pathologic processes in fatal bovine respiratory disease (brd) of feedlot cattle and to investigate associations between agents and pathologic processes. ninety feedlot calves diagnosed at necropsy with brd and 9 control calves without brd were examined, using immunohistochemical (ihc) staining and histopathologic studies. mannheimia haemolytica (mh) (peracute, acute, and subacute cases) and mycoplasma bovis (mb) (subacute, bronc ...200818512458
effects of commingling beef calves from different sources and weaning protocols during a forty-two-day receiving period on performance and bovine respiratory disease.the study objective was to determine health and performance of ranch calves from different preconditioning strategies during a 42-d receiving period when commingled with calves of unknown health histories from multiple sources. steer calves from a single source ranch (ranch) were weaned and immediately shipped to a feedlot (wean, initial bw = 247 +/- 29 kg); weaned on the ranch for 45 d before shipping, but did not receive any vaccinations (wean45, initial bw = 231 +/- 26 kg); or weaned, vaccina ...200818567723
effect of age at the time of vaccination on antibody titers and feedlot performance in beef calves.to compare antibody responses, feedlot morbidity and mortality rates, feedlot performance, and carcass value for calves vaccinated with 1 of 2 vaccination strategies and for unvaccinated control calves.200818593324
prevalence of antimicrobial resistance among bacterial pathogens isolated from cattle in different european countries: 2002-2004.the project "antibiotic resistance in bacteria of animal origin - ii" (arbao-ii) was funded by the european union (fair5-qlk2-2002-01146) for the period 2003-2005, with the aim to establish a continuous monitoring of antimicrobial susceptibility among veterinary laboratories in european countries based on validated and harmonised methodologies. available summary data of the susceptibility testing of the bacterial pathogens from the different laboratories were collected.200818611246
risk factors and impacts of clinical and subclinical mastitis in commercial meat-producing sheep flocks in quebec, canada.we conducted a prospective observational study on clinical and subclinical mastitis in 30 commercial meat-producing sheep flocks from 2 regions of the province of quebec, canada. a total of 2,792 ewes selected in late gestation were followed from lambing to weaning of lambs. the incidence of clinical mastitis for the total lactation period (average of 58 days) ranged among flocks from 0 to 6.6%, with a median of 1.2%. the most frequently isolated bacteria from the cases of clinical mastitis, in ...200818656275
laryngeal abscessation due to mannheimia haemolytica in an alpaca (vicugna pacos) cria. 200818660524
mannheimia haemolytica chimeric protein vaccine composed of the major surface-exposed epitope of outer membrane lipoprotein plpe and the neutralizing epitope of leukotoxin.mannheimia haemolytica is commonly identified in cattle with shipping fever pneumonia. vaccines currently available do not provide complete protection against the disease. in an effort to develop a vaccine that delivers the immunogenic regions of leukotoxin (lkt) a and the outer membrane protein (omp) plpe, a total of four chimeric proteins were constructed. mice were subcutaneously immunized with 25, 50 and 75 microg quantities of each chimeric protein. the specificity of the immune response wa ...200818675308
effects of experimental challenge of ewes with mannheimia haemolytica on subsequent milk composition.the objective was to describe the physicochemical changes during the early phase of subclinical mastitis and to associate them with pathological findings. a mannheimia haemolytica strain was deposited into one teat duct of 25 ewes and the clinical, bacteriological, cytological, physicochemical (ph, milk composition), gross-pathological and histological findings were subsequently recorded. the organism was consistently isolated from samples of teat duct material (140/150) but not from mammary sec ...200818680619
comparison of immunogenic properties of native and inactivated mannheimia haemolytica lkt in calves.the aim of this study was to compare the immunostimulatory properties of lkt of m. haemolytica inactivated by formaldehyde and glutaraldehyde and to evaluate the neutralizing properties of anti-lkt antibodies. the experiment was conducted on 20 black-and-white lowland calves of 100 kg body weight, assigned to 4 experimental groups. the animals were given subcutaneous vaccine injections with native lkt, lkt inactivated by formaldehyde or lkt inactivated by glutaraldehyde. the anti-lkt antibody ti ...200818683535
bighorn sheep beta2-integrin lfa-1 serves as a receptor for mannheimia haemolytica leukotoxin.mannheimia haemolytica is an important cause of pneumonia in bighorn sheep (bhs; ovis canadensis). leukotoxin (lkt), the primary virulence determinant of m. haemolytica, induces cytolysis of all subsets of leukocytes. previously, we have shown that cd18, the beta subunit of beta2-integrins, mediates lkt-induced cytolysis. however, it is not clear whether cd18 of all three beta2-integrins, lfa-1, mac-1, and cr4, mediates lkt-induced cytolysis. the objective of this study was to determine whether ...200818689665
serotyping of mannheimia haemolytica isolates from bovine pneumonia: 1987-2006.over a period of 20 years, a total of 207 mannheimia haemolytica samples were isolated from calves affected with pneumonic pasteurellosis and serotyped by the indirect haemagglutination test. serotypes a1 (102 isolates), a2 (47 isolates) and a6 (42 isolates) were most common; in addition, 16 isolates were serotypes a7, a13, a14 or untypable. the relative prevalence of serotype a6 has increased recently in japan, as has been reported from other countries. the results of this study provide useful ...200817822930
dynamin-2-dependent targeting of mannheimia haemolytica leukotoxin to mitochondrial cyclophilin d in bovine lymphoblastoid cells.exotoxins which belong to the family containing the rtx toxins (repeats in toxin) contribute to a variety of important human and animal diseases. one example of such a toxin is the potent leukotoxin (lkt) produced by the bovine respiratory pathogen mannheimia haemolytica. lkt binds to cd18, resulting in the death of bovine leukocytes. in this study, we showed that internalized lkt binds to the outer mitochondrial membrane, which results in the release of cytochrome c and collapse of the mitochon ...200818765728
characterisation of mannheimia spp. strains isolated from bovine nasal exudate and factors associated to isolates, in dairy farms in the central valley of mexico.mannheimia spp. strains obtained from bovine nasal exudates of either clinically healthy or clinically affected by respiratory tract disease animals were isolated and characterised to estimate the prevalence of isolated serotypes in dairy farms in mexico, by means of a trans-sectional descriptive study. strains were isolated and typified through biochemical and immunological tests. chi(2) or fisher statistical tests were applied, as well as odds ratio calculation and logistic regression analysis ...200817521689
disposition kinetics of moxifloxacin in lactating ewes.the present study was planned to investigate the plasma disposition kinetics and the pattern of moxifloxacin elimination in the milk of lactating ewes (n=6) following a single intravenous (iv) bolus or intramuscular (im) injections at a dosage of 5 mg/kg in all animals. a crossover study was carried out in two phases separated by 21 days. plasma and milk samples were collected serially for 72 h and moxifloxacin concentrations were assayed using high performance liquid chromatography with fluores ...200817900948
effects of lipopolysaccharide and mannheimia haemolytica leukotoxin on bovine lung microvascular endothelial cells and alveolar epithelial cells.bovine respiratory disease resulting from infection with mannheimia haemolytica commonly results in extensive vascular leakage into the alveoli. m. haemolytica produces two substances, lipopolysaccharide (lps) and leukotoxin (lkt), that are known to be important in inducing some of the pathological changes. in the present study, we examined bovine pulmonary epithelial (bpe) cell and bovine lung microvascular endothelial cell monolayer permeability, as measured by trans-well endothelial and epith ...200818032592
effective gene transfer to melanoma cells using bacterial ghosts.bacterial ghosts (bg) are cell envelopes preparations of gram-negative bacteria devoid of cytoplasmic content produced by controlled expression of phix174 plasmid-encoded lysis gene e. eight melanoma cell lines were investigated for their capacity to bind and phagocyte bg derived from escherichia coli nm522 and mannheimia haemolytica a23. high capability to bind bg was observed in almost all of the analyzed cell lines, furthermore cells were able to take up bg independently of the used bacterial ...200818164809
effect of vaccinating lambs against pneumonic pasteurellosis under new zealand field conditions on their weight gain and pneumonic lung lesions at slaughter.in a field trial, 9174 lambs from seven commercial sheep flocks with a history of subclinical pneumonia were either vaccinated with ovipast plus (intervet) or given a placebo by systematic random allocation; they were vaccinated twice at an interval of four to six weeks and grazed on pasture in the same paddocks. they were weighed at the first vaccination, 11 and 23 weeks later, and one to three days before they were slaughtered. the extent of the pneumonic lesions in their lungs was scored visu ...200818178931
serotypes a1 and a2 of mannheimia haemolytica are susceptible to genotypic, capsular and phenotypic variations in contrast to t3 and t4 serotypes of bibersteinia (pasteurella) trehalosi.mannheimia haemolytica and bibersteinia (pasteurella) trehalosi are the most common bacterial isolates that cause pulmonary diseases in ruminants worldwide. the disease is determined by specific serotypes found in cattle and small ruminants. the molecular epidemiology of strains involved in disease is important in the control of outbreaks as well as in the preparation of vaccines. this study aimed to detect the instability and variations of bacterial strains that may affect the analysis of epide ...200818179587
respiratory disease associated with bovine coronavirus infection in cattle herds in southern italy.four outbreaks of bovine respiratory disease (brd) associated with bovine coronavirus (bcov) infection in italian cattle herds were reported. in 3 outbreaks, brd was observed only in 2-3-month-old feedlot calves, whereas in the remaining outbreak, lactating cows, heifers, and calves were simultaneously affected. by using reverse transcription polymerase chain reaction (rt-pcr), bcov rna was detected in all outbreaks without evidence of concurrent viral pathogens (i.e., bovine respiratory syncyti ...200818182504
susceptibility testing of tulathromycin: interpretative breakpoints and susceptibility of field isolates.in vitro susceptibility tests were conducted on bovine and porcine respiratory pathogens isolated from european countries during 2004-2006 for susceptibility to tulathromycin using the recommended methodologies for broth microdilution. the results were compared with data from a similar survey conducted prior to launch in 1998-2001 to monitor for any shift in susceptibility. the importance of maintaining the ph of the culture media within the range 7.2-7.4 was re-affirmed as a key factor in obtai ...200818187275
effects of lamb sucking on the bacterial flora of teat duct and mammary gland of ewes.we aimed (i) to determine differences in bacterial flora of teat duct and mammary gland of ewes before and after suckling, (ii) to evaluate factors potentially affecting those. we collected samples of teat duct material and mammary secretion from 11 ewes immediately before and after sucking by lambs, as well as 120 min later. we processed samples bacteriologically and compared changes in infection by the sign test. we isolated bacteria from 3.5% duct and 1.5% secretion samples before suckling. r ...200818199254
microbial contamination of dental unit waterlines in istanbul, turkey.the water used in dental unit waterlines (duwls) acts as a coolant for the high-speed equipment and as an irrigant during dental treatments. there are kind of water tanks. duwls provide a favorable environment for microbial biofilm and multiplation primarily due to the high surface in the tubing and the character of fluid dynamics in narrow, smooth-walled waterlines. biofilms can harbour opportunist pathogens such as legionella sp., pseudomonas sp. several studies have shown that duwls have high ...200818210208
sternoclavicular joint septic arthritis and mediastinitis. a case report and review of the literature.septic arthritis of the sternoclavicular joint is rare. its causes have been reported to include immuno-compromizing diseases, intravenous drug abuse, fractures of the clavicle or catheterization of the subclavian vein. we report a case of septic arthritis of the scj in a diabetic patient following periarticular injection of steroids in the ipsilateral shoulder, as this route of infection has not been documented, to our knowledge, in the literature to date. we review the literature regarding epi ...200817187260
mycoplasma alkalescens demonstrated in bronchoalveolar lavage of cattle in denmark.mycoplasma alkalescens is an arginine-metabolizing mycoplasma, which has been found in association with mastitis and arthritis in cattle. routine bacteriological examination of 17 bronchoalveolar lavage samples from calves with pneumonia in a single herd in denmark, identified m. alkalescens in eight samples. the organism was found as a sole bacterilogical findings in five of the samples as well as in combination with mannheimia haemolytica, haemophilus somni and salmonella dublin. this is the f ...200717204146
bacterial flora and risk of infection of the ovine teat duct and mammary gland throughout lactation.we collected samples of teat duct material and mammary secretion from ewes in three farms (flock a, polyparous n=7; flock b, polyparous n=6, primiparous n=4; flock c, polyparous n=4): 14 samples immediately after lambing (before sucking of lambs), 244 samples during the suckling period and 156 samples during the milking period. conventional bacteriological techniques were used. the results were modeled using survival analysis, initially by the kaplan-meier method and then by the cox proportional ...200717208321
use of deep nasopharyngeal swabs as a predictive diagnostic method for natural respiratory infections in calves. 200717209092
disposition kinetics of difloxacin after intravenous, intramuscular and subcutaneous administration in calves.the pharmacokinetics of difloxacin (dicural) was studied in a crossover study using three groups (n = 4) of male and female friesian calves after intravenous (i.v.), intramuscular (i.m.) and subcutaneous (s.c.) administrations of 5 mg/kg body weight. drug concentration in plasma was determined by high-performance liquid chromatography using fluorescence detection. the plasma concentration-time data following i.v. administration were best fitted to a two-compartment open model and those following ...200717216308
the response of mannheimia haemolytica to iron limitation: implications for the acquisition of iron in the bovine lung.mannheimia haemolytica is the major causative agent of shipping fever, a severe pneumonia in cattle causing high morbidity and mortality. a prerequisite of successful lung colonization by m. haemolytica is the necessity to adapt to the paucity of iron. the lack of genome information has precluded an assessment of the genetic repertoire available to m. haemolytica to adapt to low iron environments. to close this knowledge-gap, we have determined 90% of a virulent m. haemolytica serotype a1 genome ...200717240088
mannheimia (pasteurella) haemolytica leukotoxin utilizes cd18 as its receptor on bighorn sheep leukocytes.pneumonia caused by mannheimia (pasteurella) haemolytica is a highly fatal disease of bighorn sheep (ovis canadensis). leukotoxin (lkt), secreted by m. haemolytica, is an important virulence factor of this organism, and is cytolytic to bighorn sheep leukocytes. previously, we have shown that cd18, the beta subunit of beta2 integrins, serves as the receptor for lkt on bovine leukocytes. furthermore, anti-cd18 antibodies inhibit lkt-induced cytotoxicity of bighorn sheep leukocytes. therefore, we h ...200717347395
specific identification of gallibacterium by a pcr using primers targeting the 16s rrna and 23s rrna genes.gallibacterium was recently established as a new genus including organisms previously reported as pasteurella anatis, [actinobacillus] salpingitidis and avian pasteurella haemolytica-like organisms. the aim of the present study was to develop a pcr method allowing unambiguous identification of gallibacterium. pcr primers positioned in the 16s rrna (1133fgal) and 23s rrna (114r) genes were defined and their specificity was subsequently tested on 122 strains. twenty-five of the strains represented ...200717350770
mannheimia haemolytica leukotoxin-induced cytolysis of ovine (ovis aries) leukocytes is mediated by cd18, the beta subunit of beta2-integrins.mannheimia (pasteurella) haemolytica causes severe pneumonia in cattle, sheep and goats. leukotoxin (lkt) is the most important virulence determinant produced by this organism. previously, we identified cd18, the beta subunit of beta(2)-integrins, as the receptor for lkt on bovine leukocytes. since lkt is specific for leukocytes of cattle, sheep and goats, we hypothesized that lkt utilizes cd18 as its receptor on ovine leukocytes as well. therefore, the objective of this study was to transfect a ...200717368825
effects of melengestrol acetate on the inflammatory response in heifers challenged with mannheimia haemolytica.previous research from our laboratory has indicated that melengestrol acetate (mga) added to the diet during the first 35 d after arrival in the feedlot improves growth rates and tends to reduce chronic respiratory disease in heifers naturally challenged with bovine respiratory disease. the current study was conducted to provide further insight into the possible immunomodulatory effects of mga. crossbred heifers (n = 48; 232 +/- 5.5 kg of bw) were used in a randomized complete block design to de ...200717371793
etiology of respiratory disease in non-vaccinated, non-medicated calves in rearing herds.the aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. according to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. tracheobronchial lavage (tbl) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncyti ...200717084565
board-invited review: recent advances in management of highly stressed, newly received feedlot cattle.morbidity and mortality from bovine respiratory disease (brd) and associated losses in performance and carcass merit continue to plague the beef cattle industry. several viral/bacterial agents are responsible for brd, and interactions occur among the agents. viral agents often predispose animals to bacterial infections, and mannheimia haemolytica is the most frequently isolated organism in cattle with brd. laboratory tests are available to characterize organisms causing brd using easily obtained ...200717085724
comparative pharmacokinetics of marbofloxacin in healthy and mannheimia haemolytica infected calves.the pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and mannheimia haemolytica naturally infected (n=8) simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. the concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (mrt) were sig ...200717118414
an aetiopathological study of chronic bronchopneumonia in lambs in ireland.chronic bronchopneumonia in lambs, also known as 'atypical' or 'chronic, non-progressive' pneumonia is a common, frequently sub-clinical disease affecting animals under 12-months-old in intensive production systems. infection with both mycoplasma ovipneumoniae and mannheimia haemolytica have been implicated in the aetiology of this condition and a variety of pulmonary lesions can result. in this study, detailed laboratory examination of 30 abattoir-derived lungs with the characteristic gross fea ...200716632391
phylogenetic diversity of pasteurellaceae and horizontal gene transfer of leukotoxin in wild and domestic sheep.wild and domestic animal populations are known to be sources and reservoirs of emerging diseases. there is also a growing recognition that horizontal genetic transfer (hgt) plays an important role in bacterial pathogenesis. we used molecular phylogenetic methods to assess diversity and cross-transmission rates of pasteurellaceae bacteria in populations of bighorn sheep, dall's sheep, domestic sheep and domestic goats. members of the pasteurellaceae cause an array of deadly illnesses including ba ...200716635591
mannheimia haemolytica and bovine respiratory disease.mannheimia haemolytica is the principal bacterium isolated from respiratory disease in feedlot cattle and is a significant component of enzootic pneumonia in all neonatal calves. a commensal of the nasopharynx, m. haemolytica is an opportunist, gaining access to the lungs when host defenses are compromised by stress or infection with respiratory viruses or mycoplasma. although several serotypes act as commensals, a1 and a6 are the most frequent isolates from pneumonic lungs. potential virulence ...200718218156
immune evasion by pathogens of bovine respiratory disease complex.bovine respiratory tract disease is a multi-factorial disease complex involving several viruses and bacteria. viruses that play prominent roles in causing the bovine respiratory disease complex include bovine herpesvirus-1, bovine respiratory syncytial virus, bovine viral diarrhea virus and parinfluenza-3 virus. bacteria that play prominent roles in this disease complex are mannheimia haemolytica and mycoplasma bovis. other bacteria that infect the bovine respiratory tract of cattle are histophi ...200718218162
analysis of gene order data supports vertical inheritance of the leukotoxin operon and genome rearrangements in the 5' flanking region in genus mannheimia.the mannheimia subclades belong to the same bacterial genus, but have taken divergent paths toward their distinct lifestyles. for example, m. haemolytica + m. glucosida are potential pathogens of the respiratory tract in the mammalian suborder ruminantia, whereas m. ruminalis, the supposed sister group, lives as a commensal in the ovine rumen. we have tested the hypothesis that vertical inheritance of the leukotoxin (lktcabd) operon has occurred from the last common ancestor of genus mannheimia ...200717915007
susceptibility of bacterial pathogens against lincomycin/spectinomycin (1/2), penicillin g/neomycin (1/1), and penicillin g/dihydrostreptomycin (1/1) as determined in the bft-germvet monitoring program 2004-2006.a total of 368 bacterial pathogens, including 72 coagulase-positive and coagulase-variable staphylococci, 97 beta-haemolytic streptococci, 51 escherichia coli, 75 pasteurella multocida, 25 mannheimia haemolytica, 25 pseudomonas aeruginosa, and 23 arcanobacterium pyogenes, were investigated for their susceptibility to the three combinations of antimicrobial agents lincomycin/spectinomycin (1/2), penicillin g/neomycin (1/1), and penicillin g/dihydrostreptomycin (1/1) in comparison to their suscept ...200717939451
teat lesions predispose to invasion of the ovine mammary gland by mannheimia haemolytica.teat lesions, produced in ewes by an experimental chapping procedure, were found to facilitate experimental infection with mannheimia haemolytica, as assessed by observations on infection of the teat skin, teat duct and mammary gland, and on the production of mastitis. the origin of the m. haemolytica strain used (ovine tonsillar or mammary infection) did not appear to influence the results. in a second experiment, in which ewes continued to suckle their lambs but were not deliberately infected, ...200717942110
accuracy of susceptibility testing of pasteurella multocida and mannheimia haemolytica.the accuracy of antimicrobial susceptibility determinations relies on the bacterial species identification and the test methodology that is being used. in the present study, both aspects were investigated for 141 pasteurella multocida and 34 mannheimia haemolytica sensu lato isolates recovered from the upper respiratory tract of healthy calves. this was performed on the one hand by comparing of classical phenotyping with tdna-pcr genotyping and on the other hand by pairwise comparison of disk di ...200717949308
use of computed tomography to evaluate pathologic changes in the lungs of calves with experimentally induced respiratory tract disease.to optimize methods for the use of computed tomography (ct) to assess pathologic changes in the lungs of calves and to determine the effect of treatment on lung consolidation.200717975983
effect of ph, temperature and nutrient limitations on growth and leukotoxin production by mannheimia haemolytica in batch and continuous culture.quantification of the effects of ph, temperature and nutrient limitations on the growth and leukotoxin (lkt) production parameters of mannheimia haemolytica in batch and chemostat culture.200717448162
differences in susceptibility to mannheimia haemolytica-associated mastitis between two breeds of dairy sheep.we used a mannheimia haemolytica isolate to study differences in susceptibility to experimental mastitis between two breeds of dairy sheep. the isolate was deposited into the teat duct of karagouniko (k, n=8) or frisarta (f, n=8) ewes. the animals were monitored by means of clinical, bacteriological, cytological and pathological methods. k ewes did not develop any systemic or mammary clinical signs, whilst f ewes became ill and developed acute clinical mastitis 12 h later (p<0.001). bacteria wer ...200717451623
clinical, bacteriological, cytological and pathological features of teat disorders in ewes.we describe the features of 13 cases of teat disorders in ewes, as follows: lengthy teats (one case), papilloma infection (two), staphylococcal dermatitis (one), nodules and abscesses (two), teat bites (three), stenosis (one), orf (two), compressed teat (one). mannheimia haemolytica, staphylococcus epidermidis, staphylococcus simulans or staphylococcus aureus were isolated from samples. sub-epithelial leucocytic infiltration at the teat duct-teat cistern border, but not lymphoid nodules, was the ...200717493169
mannheimia haemolytica leukotoxin binds to lipid rafts in bovine lymphoblastoid cells and is internalized in a dynamin-2- and clathrin-dependent manner.mannheimia haemolytica is the principal bacterial pathogen of the bovine respiratory disease complex. its most important virulence factor is a leukotoxin (lkt), which is a member of the rtx family of exotoxins produced by many gram-negative bacteria. previous studies demonstrated that lkt binds to the beta(2)-integrin lfa-1 (cd11a/cd18) on bovine leukocytes, resulting in cell death. in this study, we demonstrated that depletion of lipid rafts significantly decreases lkt-induced bovine lymphoblas ...200717682044
monomeric expression of bovine beta2-integrin subunits reveals their role in mannheimia haemolytica leukotoxin-induced biological effects.the ruminant-specific leukotoxin (lkt) of mannheimia haemolytica is the key virulence factor contributing to the pathogenesis of lung injury in bovine pneumonic pasteurellosis. previous studies by us and others indicate that m. haemolytica lkt binds to cd18, the beta subunit of bovine beta(2)-integrins on leukocytes, and that the species specificity of lkt-induced effects is resident in the beta subunit cd18 and not in the alpha subunit cd11. however, lkt also binds to the cd11a subunit of lfa-1 ...200717698568
purification of the receptor for the n-acetyl-d-glucosamine specific adhesin of mannheimia haemolytica from bovine neutrophils.the glcnac-specific adhesin from mannheimia haemolytica (mha) has been shown to participate in pathogenicity of mannheimiosis due to its capacity to adhere to tracheal epithelial cells and activate the oxidative burst of bovine neutrophils. in this work, we purified the mha receptor from bovine neutrophils (mhar) by affinity chromatography on mha-sepharose. the mhar, which corresponded to approximately 2% of the protein from cell lysate, is a glycoprotein mainly composed of glu, ala, ser, gly, a ...200717707591
characterization of a broad range antibacterial substance from a new bacillus species isolated from amazon basin.a bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16s rdna sequencing. the phylogenetic analysis indicated that this strain has low sequence similarity with most bacillus spp., suggesting a new species was isolated. the antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. the substance was inhibitory to a broad range of indicator strains, including pathogenic ...200717534601
the bacterial flora in the teat duct of ewes can protect against and can cause mastitis.we studied the possible effects of bacterial populations within the teat duct, in the pathogenesis of ovine mastitis. in experiment i, 32 ewes were allocated into group a (ewes from which we isolated (+++ growth) coagulase-negative staphylococci), b (ewes from whose duct we isolated (+ growth) coagulase-negative staphylococci) or c (ewes from which we isolated bacillus spp.) and subdivided into a1, b1, c1 (n=4; challenged by deposition of 1.250 cfu of mannheimia haemolytica into the teat duct) o ...200717540156
identification and characterization of transcriptional regulation of the mannheimia haemolytica ferric uptake regulator.the ferric uptake regulator (fur) is an iron-dependent transcriptional regulator that regulates genes related to iron acquisition, oxidative stress response, and various other functions. transcription of fur is typically self-regulating and sensitive to iron and oxidative stress. following the identification of a fur gene in the genome of the bovine pathogen mannheimia haemolytica, an attempt was made to characterize the transcriptional control of m. haemolytica fur. northern blotting, rt-pcr, a ...200717544233
characterization of carbohydrate structures of bovine muc15 and distribution of the mucin in bovine milk.the present work reports the characterization of carbohydrate structures and the distribution of the newly identified mucin muc15, a highly glycosylated protein associated with the bovine milk fat globule membrane (mfgm). distribution of muc15 was investigated in various fractions of bovine milk by densitometric scanning of western blots. in raw milk, muc15 was shown to constitute 0.08% (wt) of the protein and approximately 1.5% (wt) of the mfgm-associated proteins. surprisingly, this study show ...200717582096
integrin-egf-3 domain of bovine cd18 is critical for mannheimia haemolytica leukotoxin species-specific susceptibility.mannheimia haemolytica leukotoxin (lkta) is the primary virulence factor contributing to the pathogenesis of lung injury in bovine pneumonic pasteurellosis. results from the authors' previous studies demonstrated that the site required for lkta binding leading to susceptibility to its biological effects resides within amino acid residues 500-600 of the extracellular region of bovine cd18. experiments were designed to identify a much smaller functional domain within this 100 amino acid region of ...200717590223
transfection of non-susceptible cells with ovis aries recombinant lymphocyte function-associated antigen 1 renders susceptibility to mannheimia haemolytica leukotoxin.mannheimia haemolytica is an important etiological agent of pneumonia in domestic sheep (ds, ovis aries). leukotoxin (lkt) produced by this organism is the principal virulence factor responsible for the acute inflammation and lung injury characteristic of m. haemolytica caused disease. previously, we have shown that the leukocyte-specific integrins, beta(2) integrins, serve as the receptor for lkt. although it is certain that cd18, the beta subunit of beta(2) integrins, mediates lkt-induced cyto ...200717590539
the outer membrane protein ompa of mannheimia haemolytica a1 is involved in the binding of fibronectin.an enzyme-linked immunosorbent assay using bovine fibronectin as the substrate was used to demonstrate that mannheimia haemolytica a1 binds to fibronectin. this binding to fibronectin was specific as no binding was observed with bovine fibrinogen. the binding to fibronectin was not observed if the m. haemolytica a1 cells were pretreated with trypsin or proteinase k, suggesting that it involved a protein molecule on the cell surface. interestingly, the fibronectin-binding activity was found to be ...200717608694
an evaluation of the relative efficacy of tulathromycin for the treatment of undifferentiated fever in feedlot calves in nebraska.a field trial was performed under commercial feedlot conditions in central nebraska to assess the relative efficacy of tulathromycin (tula) to florfenicol (flor) for the treatment of undifferentiated fever (uf) in feedlot calves that did not receive a metaphylactic antimicrobial or vaccines/bacterins containing mannheimia haemolytica or histophilus somni at feedlot arrival by comparing animal health, feedlot performance, and carcass characteristic variables. two hundred recently weaned, auction ...200717616056
cd11b of ovis canadensis and ovis aries: molecular cloning and characterization.leukotoxin (lkt) is the primary virulence factor secreted by mannheimia haemolytica which causes pneumonia in ruminants. previously, we have shown that cd18, the beta subunit of beta(2) integrins, mediates lkt-induced cytolysis of ruminant leukocytes. cd18 associates with four distinct alpha subunits giving rise to four beta(2) integrins, cd11a/cd18 (lfa-1), cd11b/cd18 (mac-1), cd11c/cd18 (cr4), and cd11d/cd18. it is not known whether all the beta(2) integrins serve as a receptor for lkt. since ...200717628696
clinical mastitis in ewes; bacteriology, epidemiology and clinical features.clinical mastitis is an important disease in sheep. the objective of this work was to identify causal bacteria and study certain epidemiological and clinical features of clinical mastitis in ewes kept for meat and wool production.200717892567
pathogenic and opportunistic gram-negative bacteria in soil, leachate and air in san nicolás landfill at aguascalientes, mexico.the occurrence of gram-negative pathogenic and opportunistic species, was studied for two years on air. soil and leachate from the san nicolás landfill. aguascalientes, mexico. for soil and leachate four samplings were done, two during the dry season and two during the rainy season. for soil there were 15 sampling points, the leachate samples were taken on the leachate tank. for air, twelve sampling were done in three points of the landfill. twenty pathogenic and/or opportunistic bacteria were i ...200718693549
pneumonia of lambs in the abruzzo region of italy: anatomopathological and histopathological studies and localisation of mycoplasma ovipneumoniae.the most common forms of inflammation of the lower respiratory tract in lambs are acute enzootic pneumonia, caused mainly by mannheimia haemolytica, chronic enzootic pneumonia (defined as 'atypical' in lambs), the aetiological of which is mycoplasma ovipneumoniae and viral inflammation principally caused by parainfluenza virus type 3. the authors conducted anatomopathological and histopathological studies of the most commonly encountered spontaneous lung inflammations in lambs slaughtered in the ...200720411506
evaluation of the prevalence and onset of lung lesions and their impact on growth of lambs.to determine the prevalence and temporal onset of lung lesions in lambs and the impact of lung lesions on growth of affected lambs.200616649926
plasmid-mediated florfenicol resistance in pasteurella trehalosi.a florfenicol-resistant pasteurella trehalosi isolate from a calf was investigated for the presence and the location of the gene flor.200616670108
contribution of respiratory burst activity to innate immune function and the effects of disease status and agent on chemiluminescence responses by ruminant phagocytes in vitro.the mechanisms of interaction between phagocytes and different bacteria that help resolve lung infections or contribute to lung pathology are poorly defined. alveolar phagocytes (resident macrophages and recruited neutrophils) make a major contribution to innate immunity by mounting a respiratory burst that helps kill internalised bacteria. however, this ability may be altered during or after exposure to infection. this review considers the application and limitations of a variety of analytical ...200616678912
lung lesions in scid-bo and scid-bg mice after intratracheal inoculation with wild-type or leucotoxin-deficient mutant strains of mannheimia haemolytica serotype 1.the purpose of this study was to investigate scid-bg mice engrafted with bovine haematolymphoid tissues (scid-bo) as a model for studying bovine mannheimia haemolytica serotype 1- induced pneumonia, in which leucotoxin (lkt) plays a major role. in experiment a, scid-bo and scid-bg mice were inoculated intratracheally with either (1) phosphate-buffered saline (pbs), (2) m. haemolytica wild-type strain 89010807n ("lkt(+)wt"), (3) a m. haemolytica leucotoxin-deficient mutant of strain 89010807n ("l ...200616712865
production of a d-glycero-d-manno-heptosyltransferase mutant of mannheimia haemolytica displaying a veterinary pathogen specific conserved lps structure; development and functionality of antibodies to this lps structure.previous structural studies of the lipopolysaccharides from the veterinary pathogens mannheimia haemolytica (mh), actinobacillus pleuropneumoniae (ap) and pasteurella multocida (pm) had identified a conserved inner core oligosaccharide structure that was present in all strains investigated. in order to examine the potential of this inner core structure as a vaccine, a mutagenesis strategy was adopted to interrupt a d-glycero-d-manno-heptosyltransferase gene (losb) of mh. this gene encodes the en ...200616750602
effect of mannheimia (pasteurella) haemolytica infection on acute-phase proteins and some mineral levels in colostrum-breast milk-fed or colostrum-breast milk-deprived sheep.the aim of this study was to investigate the levels of acute-phase proteins and minerals as indicators for the reactivity in 1-year-old sheep. a total of 26 chios breed sheep were fed colostrum-breast milk (control, n = 15)or were deprived afterseparation from their mother immediately after birth(experimental, n = 11). mannheimia (pasteurella) haemolytica serotype a1 was inoculated intratracheally and blood samples were taken in vacuumed sera on days 0, 1, 4, 7, 10, 13, 16, 19 and 22. antibiotic ...200616755360
the n-acetyl-d-glucosamine specific adhesin from mannheimia haemolytica activates bovine neutrophils oxidative burst.in this work we identified specific bovine leukocytes that were bound by the mannheimia haemolytica adhesin molecule (mha) and the biological effect on the leukocytes. histochemical staining and flow cytometry showed that mha bind neutrophils (90%) and monocytes (5%). mha induced an oxidative response in purified neutrophils; this effect was 1.5-fold higher than the effect observed with control cells activated with zymosan. cellular binding by mha was inhibited with glcnac and its oligomers, as ...200616780962
characterization of a bacteriocin-like substance produced by bacillus amyloliquefaciens isolated from the brazilian atlantic forest.a bacillus strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16s rdna sequencing. phylogenetic analysis indicated that the strain has high sequence similarity with bacillus amyloliquefaciens. the antimicrobial substance was inhibitory to pathogenic and food-spoilage bacteria, such as listeria monocytogenes, bacillus cereus, serratia marcescens, and pasteurella haemolytica. it was stable over a wide temperature range, but lost activity when the temperatu ...200616835841
diversity of temperate bacteriophages induced in bovine and ovine mannheimia haemolytica isolates and identification of a new p2-like phage.the diversity of temperate bacteriophages was examined in 32 mannheimia haemolytica, six mannheimia glucosida and four pasteurella trehalosi isolates. phage particles were induced and identified by electron microscopy in 24 (75%) m. haemolytica isolates, but in only one (17%) m. glucosida and one (25%) p. trehalosi isolate. the m. haemolytica phages were relatively diverse as seven siphoviridae, 15 myoviridae and two podoviridae-like phages were identified; the myoviridae-type phages also exhibi ...200616842340
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