Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| summer mastitis caused by pasteurella haemolytica biotype a. | 1990 | 2219653 | |
| actinobacillus rossii sp. nov., actinobacillus seminis sp. nov., nom. rev., pasteurella bettii sp. nov., pasteurella lymphangitidis sp. nov., pasteurella mairi sp. nov., and pasteurella trehalosi sp. nov. | evidence from numerical taxonomic analysis and dna-dna hybridization supports the proposal of new species in the genera actinobacillus and pasteurella. the following new species are proposed: actinobacillus rossii sp. nov., from the vaginas of postparturient sows; actinobacillus seminis sp. nov., nom. rev., associated with epididymitis of sheep; pasteurella bettii sp. nov., associated with human bartholin gland abscess and finger infections; pasteurella lymphangitidis sp. nov. (the blg group), w ... | 1990 | 2223608 |
| the humoral immune response of lambs experimentally infected with mycoplasma ovipneumoniae. | using sera from lambs experimentally infected with mycoplasma ovipneumoniae and pasteurella haemolytica, the development of a good humoral immune response to m. ovipneumoniae was detected by elisa. the antibody titres peaked 41 days post-infection and good antibody titres were maintained over the 16-week experimental period. immunoblotting revealed that antibodies to specific antigens appeared in the sera in a sequential manner, some being seen shortly after infection and others developing only ... | 1990 | 2238460 |
| immune response to pulmonary injection of pasteurella haemolytica-impregnated agar beads followed by transthoracic challenge exposure in goats. | a method of inducing pasteurella haemolytica serotype 1 (ph1) lung infection in goats, using low numbers of bacteria and without impairing host immunity, was developed. two trials were conducted. results of trial 1, using 10 principals (ph1 agar beads) and 6 controls (agar beads alone), indicated that ph1 organisms imbedded in agar beads could survive host lung defenses for 32 days. results of trial 2 indicated that lung immunity in the inoculated goats (principals) was high and they were more p ... | 1990 | 2240785 |
| clinical and pathologic studies of experimentally induced pasteurella haemolytica pneumonia in calves. | pasteurella haemolytica pneumonia of the right caudal lung lobe was experimentally induced in 2-week-old holstein calves (n = 11) by endobronchial inoculation of 7.9 x 10(10) colony-forming units of 6-hour log-phase bacteria. calves were studied for 72 hours after inoculation. the challenge procedure consistently induced a lesion in the right caudal lung lobe, which was consistent radiographically with results of pathologic examination and a similar volume of bronchography contrast medium. clini ... | 1990 | 2240808 |
| pneumonic pasteurellosis induced experimentally in gnotobiotic and conventional calves inoculated with pasteurella haemolytica. | experimental pneumonia caused by pasteurella haemolytica was induced in 2-week-old gnotobiotic (n = 4) and conventional (n = 6) calves by endobronchial inoculation into the right caudal lung lobe of 7.9 x 10(10) +/- 0.6 x 10(10) (mean +/- sd) colony-forming units of p haemolytica in the 6-hour log phase of growth. the calves were studied for 24 hours or less. regression lines for the relationship between clinical index and time for the gnotobiotic group and conventional group of calves were comp ... | 1990 | 2240809 |
| hematological changes in calves exposed to a mixture of lipopolysaccharide and crude leukotoxin of pasteurella haemolytica. | the purpose of this investigation was to determine if culture supernatants of pasteurella haemolytica containing crude leukotoxin and lipopolysaccharide (clcl) causes disseminated intravascular coagulopathy (dic) when injected into calves. the effect of intraduodenal (id) exposure followed by a subsequent subcutaneous (sc) inoculation of either heat-treated or untreated clcl was evaluated. the relative contribution of the crude leukotoxin and lipopolysaccharide (lps) to the virulence of p. haemo ... | 1990 | 2249175 |
| summer mastitis caused by pasteurella haemolytica. | 1990 | 2260270 | |
| characterization of an rrna gene-specific cdna probe: applications in bacterial identification. | discontinuous dna complementary to escherichia coli 16s + 23s ribosomal rna was synthesized by random oligonucleotide priming using reverse transcriptase. cdna generated from native or denatured rrna template was labelled by incorporation of either [alpha-32p]dctp or digoxigenin-labelled dutp during synthesis, followed by template hydrolysis. the specific activity of the radiolabelled cdna was 10(7)-10(8) c.p.m. (micrograms rrna template)-1 with 60-92% incorporation after 5 h. the length of the ... | 1990 | 2262795 |
| resistance to host immune defense mechanisms afforded by capsular material of pasteurella haemolytica, serotype 1. | selected serum-mediated host immune defense mechanisms against pasteurella haemolytica were studied using encapsulated and decapsulated organisms. when the capsular material was removed from p. haemolytica, it became more susceptible to serum agglutination, complement-mediated serum killing, and phagocytosis by polymorphonuclear leukocytes. when encapsulated organisms were used, phagocytosis was enhanced by antibodies to capsular material produced by vaccination of calves with any of three p. ha ... | 1990 | 2281608 |
| a guinea pig model of bovine pneumonic pasteurellosis. | the induction of pneumonic pasteurellosis in guinea pigs (cavia porcellus) was examined. specific pathogen free male guinea pigs were anesthetized and a tracheostomy performed to introduce 10(5), 10(4) or 10(3) pasteurella haemolytica-a1 into the left principal bronchus. the surgical site was closed with tissue adhesive and staples and the animals were monitored for signs of respiratory tract infection. within 24 hours after inoculation they became depressed, anorectic, pyretic and dyspneic. fib ... | 1990 | 2306663 |
| granulocyte plasma membrane damage by leukotoxic supernatant from pasteurella haemolytica a1 and protection by immune serum. | bovine respiratory disease caused by pasteurella haemolytica may be partially mediated by a leukotoxin secreted by the microorganism. we examined the effect of leukotoxic pasteurella supernatants on leakage of the cytosol enzyme lactate dehydrogenase and the lysosomal enzyme arylsulfatase from bovine granulocytes. lactate dehydrogenase release (94%) was much higher than arylsulfatase release (38%) over 30 minutes of incubation. the pasteurella supernatants inhibited superoxide production by stim ... | 1990 | 2306664 |
| the effect of pasteurella haemolytica and the leukotoxin of pasteurella haemolytica on bovine lung explants. | bovine lung explants were used in a study designed to compare the pathogenic effects of pasteurella haemolytica type 1, a nonpathogenic organism neisseria subflava, or the crude leukotoxin of p. haemolytica on alveolar macrophages and lung parenchymal cells. concentrated, purified peripheral blood neutrophil suspensions were added with the bacteria to some explants. duplicate pairs of cultures from each treatment group were fixed at regular intervals up to 24 hours after seeding and morphologica ... | 1990 | 2306666 |
| in vitro susceptibility of selected veterinary bacterial pathogens to ciprofloxacin, enrofloxacin and norfloxacin. | the minimum inhibitory concentrations (mic) of ciprofloxacin, enrofloxacin, and norfloxacin were tested for approximately ten clinical isolates of each of actinobacillus pleuropneumoniae, actinobacillus suis, actinomyces pyogenes, corynebacterium pseudotuberculosis, erysipelothrix rhusiopathiae, haemophilus parasuis, haemophilus somnus, pasteurella haemolytica, pasteurella multocida, rhodococcus equi, streptococcus equi, streptococcus suis and streptococcus zooepidemicus. ciprofloxacin and enrof ... | 1990 | 2306672 |
| nonreciprocal complementation of the hlyc and lktc genes of the escherichia coli hemolysin and pasteurella haemolytica leukotoxin determinants. | the genetic organization of the pasteurella haemolytica leukotoxin operon (lktcabd) is similar to that of the escherichia coli hemolysin (hlycabd). their gene products share a sequence similarity of 66, 62, 90.5, and 75.6%, respectively. we investigated the role of the c proteins (lktc and hlyc) by performing reciprocal transcomplementation analyses in an e. coli recombinant background. in the absence of the c genes, neither lkta nor hlya had their respective cytotoxic activities. when hlyc was ... | 1990 | 2307519 |
| effect of pasteurella haemolytica-derived endotoxin on pulmonary structure and function in calves. | the role of endotoxin in the pathogenesis of acute pneumonic pasteurellosis is uncertain. recently, we reported that escherichia coli-derived endotoxin given by airway inoculation fails to induce lung injury in calves. because pasteurella haemolytica-derived endotoxin may differ substantially from e coli in its pathogenicity, we repeated these studies with pasteurella endotoxin. intratracheal inoculation of p haemolytica endotoxin caused hypoxemia and increased the alveolar-arterial oxygen diffe ... | 1990 | 2316921 |
| nucleotide sequence of the leukotoxin gene from actinobacillus actinomycetemcomitans: homology to the alpha-hemolysin/leukotoxin gene family. | the leukotoxin produced by actinobacillus actinomycetemcomitans has been implicated in the etiology of localized juvenile periodontitis. to initiate a genetic analysis into the role of this protein in disease, we have cloned its gene, lkta. we now present the complete nucleotide sequence of the lkta gene from a. actinomycetemcomitans. when the deduced amino acid sequence of the leukotoxin protein was compared with those of other proteins, it was found to be homologous to the leukotoxin from past ... | 1990 | 2318535 |
| use of long-acting oxytetracycline against pasteurellosis in lambs. | the efficacy of long-acting oxytetracycline in the control of pneumonic pasteurellosis in lambs was tested on seven scottish farms. after laboratory confirmation of pasteurella-related deaths in lambs, half the lambs in each flock were given long-acting oxytetracycline (20 mg/kg intramuscularly) and half were left untreated. on three farms a single treatment was given and on four farms two doses were administered four days apart. eighteen of the 878 control lambs died as a result of confirmed pa ... | 1990 | 2321337 |
| influence of pasteurella haemolytica a1 crude leukotoxin on bovine neutrophil chemiluminescence. | pasteurella haemolytica a1 crude leukotoxin (25%, vol/vol) rapidly diminished the bovine neutrophil chemiluminescence response to opsonized zymosan. this inhibition was neither prevented nor reversed by 75 mm sucrose. dilute leukotoxin did not directly stimulate neutrophil chemiluminescence nor did it alter the chemiluminescence response of the neutrophils to opsonized zymosan. | 1990 | 2323829 |
| [pasteurella haemolytica serotyping]. | forty-nine strains of pasteurella haemolytica were serotyped in a pilot study. the majority of strains were isolated from sheep which had died from fibrinous pneumonia and small numbers from cases of sepsis, polyserositis, mastitis and meningitis. serotype a2 was found to be the most prevalent: 69.4 per cent. in addition, serotype a7 with 18.4 per cent and serotypes a1 and a6, both 6.1 per cent, were identified. biotype t strains were not detected in this study. further research is required into ... | 1990 | 2336643 |
| isolation of pasteurella haemolytica from tonsillar biopsies of rocky mountain bighorn sheep. | isolations of pasteurella haemolytica were compared from tonsillar biopsies versus nasal passages for 29 free-ranging rocky mountain bighorn sheep (ovis canadensis canadensis) from central idaho. overall, p. haemolytica was isolated from 11 (38%) of 29 sheep. two (18%) of the 11 positive samples were from only nasal passages compared to eight (73%) from tonsillar biopsies. pasteurella haemolytica biotype t was isolated from tonsils of nine sheep and from nasal biopsies. pasteurella haemolytica b ... | 1990 | 2338725 |
| bovine pulmonary endothelial cell damage mediated by pasteurella haemolytica pathogenic factors. | the in vitro effects of pasteurella haemolytica components on bovine pulmonary endothelial monolayers were investigated to determine the relative role of individual bacterial factors in the pathogenesis of bovine pulmonary pasteurellosis. bovine pulmonary endothelial monolayers were treated with p. haemolytica bacterial culture supernatant (cs) and p. haemolytica lipopolysaccharide. at 22 h postinoculation, the cs produced severe damage to the endothelial cells, indicated by high 51cr release, e ... | 1990 | 2341172 |
| effect of deferoxamine pretreatment on acute pneumonic pasteurellosis and neutrophil oxidative metabolism in calves. | iron plays a central role in bacterial infections, influencing both bacterial virulence and host cellular defense mechanisms. we investigated whether iron chelation might be of benefit in the treatment of pneumonic pasteurellosis of calves. neutrophils obtained from calves previously treated with the iron chelator, deferoxamine, were studied for their responses to latex and opsonized zymosan by luminol-enhanced chemiluminescence and to phorbol myristate acetate and opsonized zymosan by superoxid ... | 1990 | 2357659 |
| effects of pasteurella haemolytica a1 culture supernatant on mechanisms controlling bovine alveolar macrophage oxygen radical production. | pasteurella haemolytica a1 culture supernatant containing leukotoxin, and modifiers of cyclic nucleotide and arachidonate metabolism, were evaluated for their ability to alter oxygen radical production by pulmonary alveolar macrophages obtained from seven holstein calves. calves were sedated, and underwent bronchoalveolar lavage to harvest macrophages, which were then incubated with culture supernatant and/or the drugs and toxins under study, and challenged with opsonized zymosan to induce oxyge ... | 1990 | 2357660 |
| a colourimetric, microplate assay for the leucotoxin of pasteurella haemolytica. | culture supernates of pasteurella haemolytica, which contain leucotoxin, inhibited the reduction of nitroblue tetrazolium (nbt) by bovine and ovine but not rabbit leucocytes in response to phorbol 12-myristate 13-acetate (pma). culture supernates of p. multocida, which contain no leucotoxin, had no inhibitory effect on the response of leucocytes from any species. the inhibition of nbt reduction was assessed visually or spectrophotometrically in the wells of microplates and used as a simple assay ... | 1990 | 2363244 |
| iron acquisition in pasteurella haemolytica: expression and identification of a bovine-specific transferrin receptor. | seven type 1 field isolates of pasteurella haemolytica were screened for their ability to use different transferrins as a source of iron for growth. all seven strains were capable of using bovine but not human, porcine, avian, or equine transferrin. a screening assay failed to detect siderophore production in any of the strains tested. iron-deficient cells from these strains expressed a binding activity, specific for bovine transferrin, that was regulated by the level of iron in the medium. inhi ... | 1990 | 2365453 |
| effects of pasteurella haemolytica leukotoxin on neutrophils from white-tailed deer and several exotic ruminant species. | pasteurella haemolytica leukotoxin is a pore-forming cytolysin which acts as a virulence factor in pasteurellosis of domestic ruminants. leukocytes from cattle, sheep and goats are susceptible to leukotoxin-induced lysis; however, leukocytes from non-ruminant species so far tested are resistant to leukotoxin-induced lysis. neutrophils obtained from three white-tailed deer, four saiga antelope, an addra gazelle, a grant's gazelle and a sable antelope were tested for susceptibility to the lytic ef ... | 1990 | 2382402 |
| [typing and virulence testing of pasteurella haemolytica field strains]. | the greater part of 145 typed pasteurella haemolytica strains from calf could be attributed to type a 1. hence, in the context of virulence testing, this is the most important type at present for calf. clearly manifest pneumonia was caused in calf by other strains of types a 2, a 6, a 12, and t 10 which were also tested for their virulence parameters. the same applied to a number of strains which had so far been characterised merely as t or a/t strains. | 1990 | 2386427 |
| characterization of envelope proteins from pasteurella haemolytica and pasteurella multocida. | a method was devised for the reproducible isolation of envelopes from pasteurella haemolytica serotype a2. it was also possible to prepare envelopes from other serotypes of p. haemolytica and pasteurella multocida using this methodology. examination of these preparations by sds-page showed major differences between strains of p. haemolytica and strains of p. multocida which allowed the clear distinction of isolates of these species. amongst the p. haemolytica serotypes it was possible to disting ... | 1990 | 2391489 |
| a group of indole-negative bovine strains with high deoxyribonucleic acid homology to pasteurella multocida. | a group of nine bovine pasteurella strains not producing indole were investigated for their taxonomic relationships with pasteurella multocida, pasteurella haemolytica and pasteurella canis. for all strains, dna-dna hybridization has revealed a high genetic relatedness at the species level to p. multocida and significantly lower homologies of only 18-41% towards p. haemolytica and 11-15% towards p. canis. guanine plus cytosine values of 38.0 to 42.1 mol% and several phenotypic characters have be ... | 1990 | 2400530 |
| clinical hypersensitivity to specific aerosol challenge in parenterally immunized calves. | this paper reports an experiment designed to demonstrate that the calf lung can be sensitized to a specific respirable challenge following parenteral immunization with a nonliving antigen (human serum albumin). the possibility that immune-mediated injury could subsequently interfere with nonspecific mucosal defenses was also investigated by infecting calves with pasteurella haemolytica after the antigen challenge and assessing pulmonary clearance of the organism. the results indicated that speci ... | 1987 | 2444157 |
| antigenic analysis of pasteurella haemolytica serovars 1 through 15 by crossed immunoelectrophoresis. | pasteurella haemolytica serovars 1 through 12, grown in broth and on agar plates, and 2 field isolates (types a1 and t10) were used to develop polyvalent crossed immunoelectrophoresis (xie) reference systems. the maximal number of antigens was revealed by xie when sonicates of agar plate-grown organisms were used as the immunogen (to produce antibodies) and as the soluble antigen for xie. antigens produced from agar plate-grown organisms were less contaminated (by antigenic components of the med ... | 1988 | 2450496 |
| monoclonal antibodies to pasteurella haemolytica serotype 1 lipopolysaccharide: demonstration of antigenic similarities among several serotypes. | murine monoclonal antibodies (mabs) were produced which were specific for pasteurella haemolytica serotype 1 lipopolysaccharide (lps). the mabs also reacted with lps present in a partially purified antigen derived from a saline extract of the organism. the epitope to which the mabs were directed was a carbohydrate which was sensitive to oxidation with periodate, had a molecular weight between 14,000 and 25,000 as determined by immunoblotting, and was present in a crude o-antigen preparation of p ... | 1988 | 2454940 |
| electron microscopic examination of cells of pasteurella haemolytica-a1 in experimentally infected cattle. | several modern electron microscopy techniques were used to examine pasteurella haemolytica (biotype a, serotype 1) (strain b122) recovered from experimentally infected cattle and in situ within the lung tissue of experimentally infected cattle. glycocalyx four to five times thicker than that seen on p. haemolytica grown in vitro was evident on bacterial cells recovered from live infected calves by pulmonary lavage. fimbriae were also present on cells recovered by lavage. a thick glycocalyx was a ... | 1988 | 2458818 |
| parainfluenza-3 virus-induced enhancement of histamine release from calf lung mast cells--effect of levamisole. | clinically healthy calves were divided into five groups. group 1 served as control; group 2 received levamisole (lev), 3 mg/kg, s.c.; group 3 was aerosolized with parainfluenza-3 virus (pi-3); group 4 received lev and pi-3 and group 5 was inoculated with pasteurella haemolytica. they were killed 6 days after virus exposure or 5-6 days after bacterial inoculation. lung mast cells were prepared by enzymatic treatment. mast cell histamine (hist) release was assayed spectrofluorometrically. total hi ... | 1988 | 2463373 |
| transmembrane pore size and role of cell swelling in cytotoxicity caused by pasteurella haemolytica leukotoxin. | pasteurella haemolytica a1 leukotoxin causes rapid (5 to 15 min) leakage of intracellular k+ and cell swelling and slower (15 to 60 min), ca2+-dependent formation of large plasma membrane defects (congruent to 100 nm) and leakage of lactate dehydrogenase from bovine lymphoma cells (bl3 cells) (k. d. clinkenbeard, d. a. mosier, a. l. timko, and a. w. confer, am. j. vet. res., in press). incubation of bl3 cells in medium made hypertonic by inclusion of 75 mm sucrose blocked leukotoxin-induced cell ... | 1989 | 2463967 |
| serum antibody response to carbohydrate antigens of pasteurella haemolytica serotype 1: relation to experimentally induced bovine pneumonic pasteurellosis. | the antibody responses to the capsular carbohydrate (cc) purified from pasteurella haemolytica serotype 1 were determined by an elisa, using 135 sera from 6 calves vaccinated with phosphate-buffered saline solution, formalin-killed p haemolytica bacterins, live p haemolytica, or an extract of p haemolytica referred to as carbohydrate-protein subunit (cps). calves vaccinated with live p haemolytica, bacterins, or cps developed serum antibodies to cc. bacterins containing freund incomplete adjuvan ... | 1989 | 2465713 |
| production and partial characterization of monoclonal antibodies to pasteurella haemolytica a1 capsular polysaccharide and lipopolysaccharide. | hybridoma-derived monoclonal antibodies (mab) against the cell surface antigens of pasteurella haemolytica serotype 1 were obtained by the fusion of murine myeloma cells (p3 x 63 - ag 8.653) with splenocytes of balb/c mice immunized with crude logarithmic growth-phase culture supernatant. initial screening was performed, using an elisa, with the same bacterial growth culture supernatant as coating antigens. further selection was done, using a panel of purified antigens--either capsular polysacch ... | 1988 | 2470277 |
| total and antigen-specific serum immunoglobulin isotype concentrations in hyperimmunized cattle that have undergone plasmapheresis. | the effects of prolonged plasmapheresis of cattle on total and antigen-specific immunoglobulin production were evaluated. five adult cows were hyperimmunized by repeated iv administration of live, logarithmic-phase pasteurella haemolytica a1 organisms. three of the cows underwent plasmapheresis daily for 3 weeks. from 2 cows, serum was only obtained periodically. anti-p haemolytica antibody was assayed by indirect hemagglutination and a kinetic-augmented, antigen-capture elisa for capsular polys ... | 1989 | 2471427 |
| elucidation of the structure of the pasteurella haemolytica serotype t10 lipopolysaccharide o-antigen by n.m.r. spectroscopy. | the aqueous-phase lipopolysaccharide isolated from pasteurella haemolytica serotype t10 cells by the phenol-water extraction method was found to be s-type lipopolysaccharide which possessed o-antigenic polysaccharide chains composed only of d-galactose residues. structural analysis of the o-polysaccharide, using a combination of 1d and 2d 1h- and 13c-n.m.r. methods, led to the identification of the disaccharide repeating-unit as [----3)-alpha-d-galp-(1----3)-beta-d-galf-(1----]n. the serological ... | 1989 | 2472201 |
| acute phase response in calves following infection with pasteurella haemolytica, ostertagia ostertagi and endotoxin administration. | the concentrations of bovine acute phase proteins were monitored in plasma following experimental infection with pasteurella haemolytica and ostertagia ostertagi and after endotoxin administration. raised levels of haptoglobin, alpha 1 proteinase inhibitor and seromucoid were detected after pasteurella infection and endotoxin administration. ceruloplasmin levels increased after endotoxin administration but not during pasteurella infection. raised levels of the four acute phase proteins were foun ... | 1989 | 2477881 |
| a high-molecular-weight fraction of smooth lipopolysaccharide in klebsiella serotype o1:k20 contains a unique o-antigen epitope and determines resistance to nonspecific serum killing. | the lipopolysaccharide (lps) o-antigen side chains of klebsiella serotype o1 have been studied by using mutants selected by resistance to a klebsiella bacteriophage designated o1-a. two classes of lps mutants were identified. the major group (90%) synthesized rough lps. the remaining 10% of the mutants produced a novel lps profile that lacked the highest-molecular-weight o-substituted molecules (hmw-lps) but still produced lower-molecular-weight o-substituted species (lmw-lps). by using antisera ... | 1989 | 2478478 |
| regulation of expression of the pasteurella haemolytica leukotoxin determinant. | the pasteurella haemolytica leukotoxin determinant is composed of four contiguous genes encoded on the same dna strand and denoted lktcabd, in the order of their genetic organization. to gain a better understanding of the expression and regulation of the leukotoxin, the transcripts and promoters of the lkt determinant were mapped. northern (rna) blot analysis revealed two sets of transcripts. one set was 3.7 and 3.4 kilobases long, encoded lktca, and comprised approximately 90% of the transcript ... | 1989 | 2478522 |
| lectin-detectable effects of localized pneumonia on airway mucous cell populations: role of cyclooxygenase metabolites. | we examined the airway secretory apparatus of adult sheep with experimental pneumonia to look for morphologic and lectin-binding correlates of increased mucus production. the animals were inoculated in the right caudal lobar bronchus either with starch broth containing pasteurella haemolytica (inf, n = 6), starch broth alone (sham, n = 6), or with p. haemolytica and subsequently treated (inf/t, n = 5) with 2 mg/kg indomethacin, subcutaneously three times daily for 6 days. in the inf and inf/t gr ... | 1989 | 2492933 |
| biochemical and serological properties of actinobacillus pleuropneumoniae biotype 2 strains isolated from swine. | the biochemical and serological properties of 21 strains of actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. for serologic typing, the indirect haemagglutination (iha) and the double gel-diffusion tests were used. on the basis of their soluble surface antigens, our a. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. all strains ... | 1989 | 2505435 |
| a crude cytotoxin vaccine protects sheep against experimental pasteurella haemolytica serotype a2 infection. | three vaccines containing pasteurella haemolytica serotype a2 antigens were tested for their ability to protect sheep against a homologous challenge. a crude cytotoxin preparation in combination with a sodium salicylate extract (sse) or crude cytotoxin alone were highly protective (98 and 86%, respectively), whereas sse alone was poorly (47%) protective. these findings indicated that the crude cytotoxin was an essential component of a protective vaccine. protection correlated with serum cytotoxi ... | 1989 | 2523176 |
| protection of lambs against experimental pneumonic pasteurellosis by transfer of immune serum. | passive protection of specific pathogen-free lambs against experimental pasteurellosis was achieved using antisera from conventionally reared sheep which were either convalescent from experimental pneumonia or inoculated with pasteurella haemolytica a2 vaccines. the complete immune sera, or immunoglobulin-rich fractions prepared from them, when administered separately or together provided 94-100% protection of recipients compared to control lambs. antibodies to p. haemolytica in donor sera were ... | 1989 | 2527437 |
| [experimental mycoplasma bovis infection of the respiratory tract of calves]. | multiple intranasal experimental mycoplasma (m.) bovis infection was induced to 22 calves and resulted in clinical manifestations. m. bovis was re-isolated from 17 of 24 lungs which had been altered by pneumonia. pasteurella haemolytica was the only pathogen isolated from the pathologically affected lung of one of the experimental animals. the haematogenic proliferation phase was successfully identified in 5 of 8 examined calves. arthritis was not recordable from any of the experimental animals. ... | 1989 | 2533482 |
| in vitro assessment of the efficacy of erythromycin in combination with oxytetracycline or spectinomycin against pasteurella haemolytica. | the effects of combining erythromycin (ery) with oxytetracycline (oxy) or spectinomycin (sp) on pasteurella haemolytica were evaluated in vitro using the chessboard (checkerboard) technique. these combinations were selected because all are drugs widely used in bovine respiratory disease treatment, and they represent possible sequential or complementary mechanisms of action. using the recommended breakpoints of greater than 4 micrograms/ml for ery, 16 micrograms/ml for oxy, and 32 micrograms/ml f ... | 1989 | 2535123 |
| clinical and microbiologic findings in lambs inoculated with pasteurella haemolytica after infection with ovine adenovirus type 6. | colostrum-deprived lambs (10 to 20 days old) were inoculated with either ovine adenovirus type 6 (oav-6; n = 6), pasteurella haemolytica type a1 (n = 6), or oav-6 followed by p haemolytica 5 days later (n = 10). another group (n = 3) served as sham-inoculated controls. lambs inoculated with oav-6 or p haemolytica developed mild and moderate respiratory tract disease of 6 and 3 days' duration, respectively. lambs inoculated with virus and bacteria developed clinical signs of respiratory tract dis ... | 1989 | 2543241 |
| infection of the middle nasal meatus of calves with pasteurella haemolytica serotype 1. | eight healthy nonstressed calves were inoculated with pasteurella haemolytica serotype 1, by instilling a broth culture into the middle nasal meatus of the left nostril. the inoculated left nostrils shed p haemolytica from the ventral nasal meatus at a steady rate for a mean of 7 days, whereas the uninoculated right nostrils of the same calves shed p haemolytica sporadically and in lower concentrations. the duration, frequency, and concentration of p haemolytica shed from the inoculated nostrils ... | 1989 | 2551200 |
| histological changes in lungs of calves exposed to an aerosol of pasteurella haemolytica. | an experiment was designed to study the interaction of pasteurella haemolytica with an attenuated bovine herpesvirus 1 in calves. low titre of the virus culture used for aerosol exposure failed to produce measurable interaction. however, the experiment provided the first opportunity to study the light-microscopic changes in lungs of calves (n = 3) to a low-dose exposure (5-min aerosol) of p. haemolytica a1 from a fresh 5-h log-phase culture. the histopathological study was confined to tissue exp ... | 1989 | 2551938 |
| parainfluenza 3 vaccination of sheep. | outbreaks of pneumonia associated with pasteurella haemolytica have occurred in sheep in the area of perthshire served by this practice, and on some farms the disease has been an important annual cause of loss. serological evidence was obtained that parainfluenza 3 (pi3) virus might be implicated as a predisposing factor to pasteurellosis. a live attenuated pi3 virus vaccine licensed for use in cattle was given intranasally to ewes on one farm. many sheep seroconverted and outbreaks of pneumonia ... | 1989 | 2556831 |
| efficacy of a live pasteurella multocida vaccine for the prevention of experimentally induced bovine pneumonic pasteurellosis. | seventeen holstein-friesian calves weighing an average of 139.8 +/- 13.5 (mean +/- standard deviation) kg were used in a study to determine the efficacy of a live vaccine containing of pasteurella multocida a:3 and pasteurella haemolytica a:1. eleven calves received the vaccine by intramuscular injection in the right shoulder, whereas six calves received vaccine diluent and served as non-vaccinated controls. fourteen days following vaccination (day 15) all calves were inoculated deep intranasall ... | 1989 | 2558441 |
| presence of bacterial glycocalyx and fimbriae on pasteurella haemolytica in feedlot cattle with pneumonic pasteurellosis. | this investigation was conducted to determine if pasteurella haemolytica within feedlot cattle affected by pneumonic pasteurellosis express fimbriae (pili) and bacterial glycocalyx. bacteriological culture of pulmonary tissue from three calves with fibrinous pneumonia resulted in heavy growth of p. haemolytica. transmission electron microscopy of the lungs showed numerous microcolonies of gram-negative bacteria with morphology typical of pasteurella haemolytica. the cells within these microcolon ... | 1989 | 2565756 |
| induction of pulmonary antibodies to pasteurella haemolytica following intraduodenal stimulation of the gut-associated lymphatic tissue in cattle. | the induction of pulmonary antibodies to a bacterial antigen following intraduodenal (d) stimulation of the gut-associated lymphatic tissue (galt) was investigated. six calves were divided into two groups of three calves each. the galt-primed calves received an id dose of live pasteurella haemolytica a1 followed by a subcutaneous (sc) dose of killed p. haemolytica. the sham-primed calves received an id dose of phosphate-buffered saline solution (pbss) followed by a sc dose of killed bacteria. se ... | 1989 | 2590869 |
| isolation of pasteurella haemolytica from teat lesions in ewes. | 1989 | 2595976 | |
| serum igg and igm antibody response in cattle to antigens of pasteurella haemolytica. | the serum igg and igm antibody responses of 48 cattle vaccinated with live pasteurella haemolytica (live), formalin-killed p. haemolytica in freund's incomplete adjuvant (fia), or formalin-killed p. haemolytica in aluminum hydroxide adjuvant (alh) to a variety of p. haemolytica antigens were evaluated. enzyme-linked immunosorbent assays (elisas) were used to determine the sequential and day 21 igg and igm antibody responses to whole p. haemolytica (wb), a capsular carbohydrate-protein subunit (c ... | 1989 | 2603385 |
| iron-repressible outer-membrane proteins of pasteurella haemolytica. | the outer-membrane protein (omp) profile of pasteurella haemolytica grown under iron-replete and iron-restricted conditions was studied by polyacrylamide gel electrophoresis and immunoblotting. a serotype 1 isolate induced the synthesis of a new 77,000 mr omp in iron-restricted media while two other proteins of 100,000 mr and 71,000 mr were synthesized in increased amounts. none of these proteins were peptidoglycan-associated or heat-modifiable, and only the 100,000 mr protein showed some degree ... | 1989 | 2614386 |
| purification and characterization of a 94-kda pasteurella haemolytica antigen. | a 94-kda antigen of pasteurella haemolytica serotype 1, which was previously shown to elicit serum and nasal secretion antibody response to the bacterium, was purified and characterized. the antigen was purified by high performance liquid chromatography utilizing ion exchange, then size exclusion columns. it was a membrane protein that was copurified with 6-7% lipopolysaccharide. it had an isoelectric point of 4.6. most other serotypes of p. haemolytica possessed a similar antigen. | 1989 | 2623797 |
| antibody response to haemophilus somnus fc receptor. | to characterize the bovine immune response to an haemophilus somnus antigen known to be recognized by convalescent-phase serum, we studied isotypic antibody titers to the 270-kilodalton protein, which we had previously shown to be an immunoglobulin fc receptor. with a modified immunodot procedure, an immune response was detected after experimental h. somnus abortion, experimental h. somnus pneumonia, or vaccination with commercial h. somnus vaccine, with the greatest titer found within the immun ... | 1989 | 2643614 |
| identification and expression of the actinobacillus actinomycetemcomitans leukotoxin gene. | the leukotoxin produced by the oral bacterium actinobacillus actinomycetemcomitans has been implicated in the pathogenesis of juvenile periodontitis. in order to elucidate the structure of the leukotoxin, molecular cloning of the leukotoxin gene was carried out. a dna library of a. actinomycetemcomitans, strain jp2, was constructed by partial digestion of genomic dna with sau3ai and ligation of 0.5 to 5.0 kilobase pair fragments into the bam hi site of the plasmid vector penn-vrf. after transfor ... | 1989 | 2647082 |
| functional and metabolic activity of bovine pulmonary lavage cells phagocytically stimulated with pathogenic isolates of pasteurella haemolytica. | live pasteurella haemolytica biotype a, serotype 1 isolates (n = 3) and escherichia coli k-12, strain w3110, were reacted with bovine pulmonary lavage cell (plc) suspensions. the comparative effects of the different bacteria on the functional and metabolic activity of alveolar macrophages (amo) in the plc suspensions were assessed simultaneously by use of 51cr release, luminol-dependent chemiluminescence (ldcl), and amo bactericidal assays. the bovine plc responded differently to e coli, than to ... | 1989 | 2648902 |
| experimental infections of goats with mycoplasma mycoides subspecies mycoides, lc type. | in five experiments 29 goats were infected experimentally by five different routes with a strain of mycoplasma mycoides subspecies mycoides, lc type, isolated from a contagious caprine pleuropneumonia-like outbreak on a farm in northern sweden. all the goats were colonised except those inoculated subcutaneously with small doses. in its pattern of pathogenicity this strain was similar to other experimentally tested strains except that peroral infection in kids produced no clinical signs. a 'conta ... | 1989 | 2649950 |
| detection and interspecies-transformation of a beta-lactamase-encoding plasmid from pasteurella haemolytica. | pasteurella haemolytica-cultures, isolated from cattle with respiratory diseases, were investigated for their biotype, serotype, antimicrobial resistance and plasmid content. a plasmid encoding a beta-lactamase could be demonstrated in 9 of 19 pasteurella haemolytica-cultures. these 9 cultures, all belonging to biotype a and serotype 1, were resistant to ampicillin, carbenicillin, penicillin g and ticarcillin. the plasmid of the respective cultures proved to be identical upon southern blot hybri ... | 1989 | 2652948 |
| comparison of the pasteurella haemolytica a1 envelope proteins obtained by two cell disruption methods. | the french pressure cell and sonication methods of bacterial cell disruption were compared for the evaluation of surface proteins from pasteurella haemolytica a1. several protein bands were quantitatively different when compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and densitometry. with densitometry, sonicated preparations had higher concentrations of the 102-, 83-, 50-, 38-, and 30-kilodalton (kda) proteins; french pressure cell preparations had higher ... | 1989 | 2656741 |
| comparison of pathophysiologic changes in the lungs of calves challenge exposed with escherichia coli-derived endotoxin and pasteurella haemolytica, alone or in combination. | pulmonary responses to intratracheal challenge exposure with pasteurella haemolytica, with or without escherichia coli-derived endotoxin, e coli endotoxin alone, or saline solution were compared in anesthetized, mechanically ventilated neonatal calves. baseline values for dynamic compliance, total pulmonary resistance, functional residual capacity, arterial blood gas tensions, hemogram, leukogram, and systemic and pulmonary arterial pressures were recorded for each calf. after baseline data were ... | 1989 | 2658695 |
| synthesis and antimicrobial evaluation of 20-deoxo-20-(3,5-dimethylpiperidin-1-yl)desmycosin (tilmicosin, el-870) and related cyclic amino derivatives. | a series of 20-deoxo-20-cyclic (alkylamino) derivatives of tylosin, desmycosin, macrocin and lactenocin was prepared by reductive amination of the c-20 aldehyde group. the majority of the compounds were prepared using metal hydrides (sodium cyanoborohydride or sodium borohydride) as the reducing agents and a suitable cyclic alkylamine. subsequently, a more convenient procedure was developed using formic acid as a reducing agent. the c-20 amino derivatives prepared from desmycosin exhibited good ... | 1989 | 2668243 |
| analysis of the actinobacillus actinomycetemcomitans leukotoxin gene. delineation of unique features and comparison to homologous toxins. | actinobacillus actinomycetemcomitans leukotoxin has been implicated as a virulence factor in human infections. to initiate delineation of leukotoxin structure/function relationships, molecular cloning of the leukotoxin gene was carried out. when an a. actinomycetemcomitans genomic dna library in lambda embl3 was screened using a 1.3-kilobase pair restriction fragment containing a portion of the leukotoxin gene, 13 positive recombinants were identified. one recombinant, designated lambda op8, con ... | 1989 | 2670940 |
| the evolution of vaccines for bovine pneumonic pasteurellosis. | since the early 1900s bovine pneumonic pasteurellosis has been recognised as a major economic problem to european and north american cattle industries. initial attempts to prevent the disease were complicated by incomplete knowledge of the causative organisms. despite some early reports of vaccine-induced protection against disease, initial vaccines were of questionable protective value. from the late 1950s to the 1970s pasteurella haemolytica and p multocida bacterins were the primary type of v ... | 1989 | 2672200 |
| secretion of the pasteurella leukotoxin by escherichia coli. | nucleic acid sequence analysis has indicated that the leukotoxin determinant from pasteurella haemolytica is related to the hemolysin determinant from e. coli. the cloning and expression in e. coli of the lktca genes has been previously reported, but the existence of leukotoxin secretory genes equivalent to hlybd has not been documented. in this report we demonstrate that a 4.0 kb segment of p. haemolytica genomic dna distal to the lkta gene, when expressed in trans to the previous cloned lktca ... | 1989 | 2673918 |
| immunoserological comparison of 104-kilodalton proteins associated with hemolysis and cytolysis in actinobacillus pleuropneumoniae, actinobacillus suis, pasteurella haemolytica, and escherichia coli. | a homologous polyclonal antibody was produced in a rabbit to the 104-kilodalton (kda) protein hemolysin of actinobacillus pleuropneumoniae serotype 1 strain cm-5. in immunoblots, this antibody recognized a similar 104-kda protein produced in culture supernatants by a. pleuropneumoniae serotypes 1 to 12 and taxon "minor group" in addition to pasteurella haemolytica, actinobacillus suis, and alpha-hemolysin-producing escherichia coli (but only weakly in the latter two organisms). these results wer ... | 1989 | 2674017 |
| structure-activity studies of 20-deoxo-20-amino derivatives of tylosin-related macrolides. | reductive amination of the c-20 aldehyde group of tylosin and related macrolides yielded a large series of derivatives with potentially useful antibiotic properties. evaluation of these new compounds was conducted on the basis of: 1) broad antimicrobial spectrum in vitro, with particular emphasis on inhibition of pasteurella multocida and pasteurella haemolytica; 2) in vivo efficacy, especially when given orally, against p. multocida in experimental infections in chicks; and 3) bioavailability a ... | 1989 | 2684947 |
| immunoperoxidase evaluation of pneumonic lesions in calves naturally infected with pasteurella haemolytica. | immunoperoxidase technique was applied for pathological study on naturally occurring pneumonic tissues of calves from which pasteurella haemolytica was isolated. multifocal necrosis occurred in the lungs of 25 out of 42 calves (59.5%) and p. haemolytica antigen was detected in 22 out of the 25 calves (88.0%). the calves were divided into 3 groups according to the number of p. haemolytica isolated. the positive rate of the bacterial antigen detected by the technique was 66.6% (28/42) on the avera ... | 1989 | 2689742 |
| structures of neutral glycans isolated from the lipopolysaccharides of reference strains for serratia marcescens serogroups o16 and o20. | neutral polymers have been isolated from the lipopolysaccharides of the reference strains for serratia marcescens o16 and o20, serogroups which exhibit significant cross-reactivity. both organisms produce a galactan with the disaccharide repeating-unit shown, and which apparently accounts for the serological observations. the same galactan has also been reported as the o4-specific polysaccharide of pasteurella haemolytica. in s. marcescens o16, the galactan is apparently accompanied by a polymer ... | 1989 | 2692814 |
| cloning and characterization of a hemolysin gene from actinobacillus (haemophilus) pleuropneumoniae. | neutralizing antisera to the leukotoxin secreted by pasteurella haemolytica neutralized the hemolysin of actinobacillus pleuropneumoniae and recognized a 110-kd antigen in cell-free culture supernatants from this organism. a series of nine overlapping recombinant phage clones carrying the gene for this 110-kd antigen were identified using affinity-purified anti-hemolysin antibody and a dna probe containing sequences from the p. haemolytica lktca genes. eight of the nine clones expressed a 110-kd ... | 1989 | 2693022 |
| a plasmid which can be transferred between escherichia coli and pasteurella haemolytica by electroporation and conjugation. | three broad-host-range plasmids (prk290, psa4 and pkt230) and one native pasteurella haemolytica plasmid (pph33) were used in transformation experiments with p. haemolytica strains t179 (serotype a1), y216 (serotype a2) and its capsular-deficient variant y216/ns1. no transformants were detected with either heat-shock or freeze-thaw techniques. however, by electroporation, all p. haemolytica strains were transformed by pph33 but not by prk290 or psa4. the highest frequency obtained was 91 x 10(4) ... | 1989 | 2693589 |
| characterization of pasteurella haemolytica strains isolated from goats in hungary. | thirty-five pasteurella haemolytica strains were isolated in hungary from goat carcasses sent for postmortem examination from two farms with large goat flocks. all strains belonged to biotype a and with the exception of one strain of serotype a8 they belonged to serotype a2. no untypable strains were found by the indirect haemagglutination test. | 1989 | 2697144 |
| agarose soy casein digest medium for replacement of blood agar for potency determinations of live pasteurella vaccines. | blood agar, prepared with trypticase (bbl microbiology systems, cockeysville, md.) soy agar and 5% defibrinated bovine blood, is used for testing the potency of live pasteurella multocida and pasteurella haemolytica vaccines, but its potential for variation makes it undesirable to use in a standard assay method. tests done with rpmi 1640 and trypticase soy medium indicated that the benefits obtained by adding defibrinated blood to the trypticase soy agar medium were more likely due to neutraliza ... | 1989 | 2705764 |
| dna sequence of the pasteurella haemolytica leukotoxin gene cluster. | bovine serum was used to identify a recombinant phage clone carrying the pasteurella haemolytica leukotoxin gene. this fragment produced the 102-kd leukotoxin and several smaller p. haemolytica-specific protein antigens in escherichia coli. an additional contiguous fragment, containing sequences upstream from the leukotoxin gene. using these clones, we determined the nucleotide sequence of a 7745-bp region that included four open reading frames: an upstream gene, lktc; the leukotoxin gene, lkta; ... | 1989 | 2707120 |
| cloning and expression of the leukotoxin gene from actinobacillus actinomycetemcomitans. | the leukotoxin produced by actinobacillus actinomycetemcomitans has been implicated in the etiology of juvenile periodontitis. to initiate a genetic analysis of the role of this protein in disease, we have cloned the leukotoxin gene in escherichia coli. recombinant colonies carrying toxin gene sequences were isolated by screening a genomic a. actinomycetemcomitans library with a dna probe for the leukotoxin gene from a related bacterium, pasteurella haemolytica. to demonstrate that the cloned a. ... | 1989 | 2707855 |
| a new serovar of pasteurella haemolytica from sheep in syria. | 1989 | 2711467 | |
| antibodies to pasteurella haemolytica somatic antigens in two models of the bovine respiratory disease complex. | serum samples obtained from feeder calves before and after entry into the market system (days 0 to 7) were assayed for antibodies to pasteurella hamolytica biotype a, serotype 1 capsular polysaccharide (cps) and lipopolysaccharide/outer membrane protein (lpsp) by isotype in a kinetic-augmented, antigen-capture elisa. these test results, plus indirect hemagglutination (iha) antibody titers, and hemolysin-in-gel test (higt) findings were compared with clinical performance data during the initial 4 ... | 1989 | 2712411 |
| effect of pasteurella haemolytica (a1) capsular polysaccharide on sheep lung in vivo and on pulmonary surfactant in vitro. | capsular polysaccharide (cp) of pasteurella haemolytica (type a1) was first deposited by fiberoptic bronchoscopy into the lungs of sheep to examine lesions and changes in bronchoalveolar lavage cell populations and, later, was mixed with pulmonary surfactant to investigate alterations in physical properties or surface tension. at 22 hours after deposition, minimal lesions were seen in the lungs only at and contiguous to the site of cp deposition in 2 of 4 sheep. microscopically, alveoli and inte ... | 1989 | 2712422 |
| 2',5' oligoadenylate synthetase activity in bovine peripheral blood mononuclear cells following bovine herpesvirus type-1-induced respiratory disease: a prognostic indicator? | following aerosol-challenge of nonimmune calves with bovine herpesvirus type-1 (bhv-1) the levels of 2',5' oligoadenylate (2-5a) synthetase in peripheral blood mononuclear cells (pbml) increased significantly to peak 4-5 days after bhv-1 infection. this corresponded temporally to the period of highest susceptibility to secondary bacterial infection. ten days post virus infection, the enzyme levels had returned to baseline values. aerosol challenge with bacteria (pasteurella haemolytica) did not ... | 1989 | 2715670 |
| modulation of bovine neutrophil antibacterial activities by pasteurella haemolytica a1 purified capsular polysaccharide. | preincubation of bovine neutrophils with pasteurella haemolytica a1 purified capsular polysaccharide markedly diminished their ability to ingest and kill p. haemolytica, but not escherichia coli, in vitro. ingestion and killing were impaired even when the p. haemolytica were preopsonized, thus suggesting that the inhibitory effects of the polysaccharide included a direct effect on bovine neutrophils rather than simply competition for serum opsonins. preincubation of neutrophils with purified pol ... | 1989 | 2716512 |
| blood bactericidal assay (pasteurella haemolytica) comparison of morbidity in marketed feeder calves. | an in vitro bactericidal assay that used bovine heparinized blood was investigated for its usefulness in detecting differences in the bactericidal immunity of calves against pasteurella haemolytica serotype 1 (ph1). greater than 90% of killing occurred within 30 minutes. the substitution of fetal calf serum for autologous calf plasma caused loss of bactericidal activity of the blood. decomplemented calf serum also was low in bactericidal activity. the blood bactericidal assay appears to be opson ... | 1989 | 2719384 |
| effects of pasteurella haemolytica leukotoxin on cultured bovine lymphoma cells. | leukotoxin activity from culture supernatants of pasteurella haemolytica serotype 1 in logarithmic growth phase caused rapid (less than 5 min) release of intracellular k+, uptake of extracellular ca2+, and swelling of cultured bovine lymphoma cells (bl3 cells). release of 51cro4(2-) and lactate dehydrogenase (ldh) from bl3 cells began after 15 minutes of incubation with leukotoxin at 37 c and was completed between 60 and 120 minutes of incubation. in addition, leukotoxin exposure of bl3 cells re ... | 1989 | 2719393 |
| antibody complement-dependent bacteriolysis in experimentally induced pasteurellosis in mice. | affinity-purified bovine immunoglobulin isotypes were bacteriolytic for pasteurella haemolytica biotype a, serotype 1 (pha-1). this bacteriolysis was specific and complement-dependent. the igm and igg1 were the most active isotypes in the classic complement cascade. these isotypes also induced bacteriolysis through the alternative complement cascade. the comparative bacteriolytic activities of igg1 and igm were equal within each cascade; however, the bacteriolytic activities of igg1 and igm were ... | 1989 | 2729722 |
| effects of parenteral selenium and vitamin e on performance, health and humoral immune response of steers new to the feedlot environment. | five trials with steers new to the feedlot environment were conducted to determine the effects of one or two i.m. injections of selenium (se) and(or) vitamin e (vit e) on performance, health status and serum antibody response to pasteurella haemolytica vaccination. in all trials, performance and average number of days sick per steer were not affected (p greater than .05) by single injection of se and(or) vit e. in trial 1, 26 steers (avg initial wt 267 kg) were treated with 1) no se or vit e or ... | 1989 | 2737988 |
| observations on sudanese camel nasal myiasis caused by the larvae of cephalopina titillator. | forty-four camels slaughtered at nyala abattoir, western sudan, were examined for infection with the larvae of cephalopina titillator. the infection rate was found to be 100 p. 100. the parasitic burden ranged between 8-243 per animal. they were recovered throughout the year. the first stage larvae were noticed from december to may, indicating the breeding season of the fly. the larvae were found to cause visible pathological lesions on the nasopharynx. these were also demonstrated histopatholog ... | 1989 | 2740563 |
| calcium ion involvement in the action of pasteurella haemolytica leukotoxin. | the influence of ca2+ ions on the cytotoxic activity of pasteurella haemolytica leukotoxin was investigated. the divalent cation influenced the cytotoxic effect of the leukotoxin for sensitive bl-3 target cells, but its absence did not eliminate cytotoxicity. in short-term 1-h assays using neutral red uptake as a measure of cell viability, depletion of ca2+ either by exhaustive dialysis or by addition of the ca2+ chelators edta and egta eliminated the cytolytic effect of low doses of the toxin. ... | 1989 | 2750075 |
| pasteurella haemolytica-like bacterium from a progressive granuloma of cattle in brazil. | three strains of a pasteurella haemolytica-like bacterium were isolated from lesions of a progressive granuloma of cattle in southern brazil. their characteristics and their differentiation from p. haemolytica varieties and actinobacillus lignieresii are described. the name "pasteurella granulomatis" is proposed for this apparently new taxon. | 1989 | 2754010 |
| evidence that blood-borne infection is involved in the pathogenesis of bovine pneumonic pasteurellosis. | five calves were inoculated intravenously with 10(8) colony forming units (cfu) of pasteurella haemolytica a1; the mean score for pneumonic consolidation 3 days post-inoculation was 28%, and the mean clinical score was 7.8. five calves inoculated intratracheally with 10(9) cfu of the same strain of p. haemolytica had comparable scores (34% and 8.8). histological lesions of fibrinous pneumonia were similar in all calves. p. haemolytica was recovered from all but one of the affected lungs. from on ... | 1989 | 2763414 |
| the frequency, distribution and effects of antibodies, to seven putative respiratory pathogens, on respiratory disease and weight gain in feedlot calves in ontario. | during 1983-85, 279 calves requiring treatment for bovine respiratory disease and 290 comparison (control) animals from 15 different groups of feedlot calves were bled on arrival and again at 28 days postarrival. their sera were then analyzed for antibodies to seven putative respiratory pathogens. on arrival, the prevalences of indirect agglutination titers to pasteurella haemolytica, p. haemolytica cytotoxin, mycoplasma bovis and m. dispar were greater than 50%, the prevalence of titers to bovi ... | 1989 | 2766158 |
| effect of a new macrolide antibiotic (tilmicosin) on pneumonia experimentally induced in calves by mycoplasma bovis and pasteurella haemolytica. | two gnotobiotic calves were treated once with tilmicosin (20 mg kg-1) six hours before they were infected by the intratracheal route with mycoplasma bovis and pasteurella haemolytica serotype 1. this treatment prevented colonisation of the lungs by p haemolytica and considerably reduced colonisation by m bovis, and the clinical scores and the extent of pneumonic consolidation, compared with two untreated gnotobiotic calves, both of which had to be killed in extremis for humanitarian reasons with ... | 1989 | 2772410 |
| serum and tissue concentrations of erythromycin in calves with induced pneumonic pasteurellosis. | the effects of pneumonia on the pharmacokinetics of erythromycin administered im and the tissue concentration changes with time were evaluated in 2-month-old calves. pneumonia was induced by injection of pasteurella haemolytica cultures through the thoracic wall into each lung. six days prior to induction of pneumonia, erythromycin (15 mg/kg) was administered in a single im dose. erythromycin was administered again 48, 72, and 96 hours after injection of p haemolytica. on the third day of erythr ... | 1989 | 2774339 |
| effects of pasteurella haemolytica leukotoxin on isolated bovine neutrophils. | p. haemolytica leukotoxin caused rapid leakage of intracellular k+ (greater than 90% in 30 sec) from and cell swelling (approximately 100% increase in 15 min) of isolated bovine neutrophils. incubation media made hypertonic by the addition of raffinose, dextran or inulin (carbohydrates with mol. wts of greater than or equal to 505) prevented leukotoxin-induced cell swelling, but not k+ leakage. assuming that leukotoxin acts as a transmembrane molecular sieve, then the leukotoxin-induced function ... | 1989 | 2781580 |
| bovine serum and nasal secretion immunoglobulins against pasteurella haemolytica serotype 1 antigens. | experimental intranasal inoculation of cattle with pasteurella haemolytica serotype 1 resulted in a group that shed the bacteria in their nasal secretions (colonized) and a group that did not shed (uncolonized). after inoculation, antibody titers in serum and nasal secretions against the total p haemolytica increased significantly, and the proportions of total antibody against specific p haemolytica antigens changed so that the proportion directed against the 94- and 62-kd antigens increased. pr ... | 1989 | 2782707 |
| comparing different isolates of pasteurella haemolytica from beef calves using their in vitro antimicrobial sensitivity patterns. | in vitro studies, using disc diffusion and agar dilution techniques, were carried out to compare susceptibilities to selected antimicrobial agents of 30 isolates of pasteurella haemolytica from healthy calves and 30 isolates from calves with transit fever. there was no difference in susceptibility patterns between isolates from healthy calves and isolates from diseased calves or between isolates of serotype a1 and isolates of serotype a2. penicillin resistance was associated with production of b ... | 1989 | 2788327 |