Kansenshogaku Zasshi, 1991 Oct, 65(10), 1365 - 8 {A case of Pasteurella multocida subsp . multocida complicated with diabetes mellitus}; Yada T et al.; We report a case of sepsis who died caused by Pasteurella multocida subsp . multocide sepsis . A 68-year-old male was admitted to Azusawa Hospital because of disturbance of consciousness . He had been suffering from diabetes mellitus combined with gangrene, but received no treatment . The patient died 24 h after hospitalization, and Pasteurella multocida subsp . multocida was isolated from his blood . Laboratory tests showed that CRP; 5+ WBC; 15,400/microliters, TP; 5.2 g/dl . Although Pasteurella multicida subsp . multocida seemed to cause mild infection in healthy subjects, it can cause severe systemic illnesses such as sepsis and meningitis in compromised hosts . It should be considered that the contact with pets will increase the incidence of systemic severe infection with this agents. Can J Vet Res, 1991 Oct, 55(4), 341 - 6 The microbial flora of the respiratory tract in feedlot calves: associations between nasopharyngeal and bronchoalveolar lavage cultures; Allen JW et al.; The upper and lower respiratory tracts of 59 feedlot calves with clinical signs of naturally occurring respiratory disease (cases) and 60 comparison (control) animals were cultured before treatment, using nasopharyngeal swabs (NPS) and bronchoalveolar lavage (BAL) . The most prevalent organisms were Pasteurella multocida and Mycoplasma bovis . Isolations of P . multocida from NPS and BAL fluid were found to be significantly associated with morbidity (p less than or equal to 0.05), but the frequency with which other organisms were isolated from the nasopharynx and lungs was similar in cases and controls . There was evidence of moderate agreement between NPS and BAL isolates at the individual calf level using the kappa statistic, (range of kappa values = 0.47-0.61) but the variability of the kappa statistics was large . Therefore, in an individual calf NPS cultures did not accurately predict BAL cultures . The NPS and BAL culture results were quite similar at the group level, however. Zentralbl Veterinarmed B, 1991 Oct, 38(8), 599 - 609 Genomic distribution of a serotype 1-specific antigen-coding DNA fragment of Pasteurella haemolytica; Gonzalez C et al.; A genomic fragment of Pasteurella haemolytica biotype A coding for a serotype 1-specific agglutinating antigen was used as a probe in a series of hybridization experiments to determine distribution of the fragment in various P . haemolytica serotypes as well as other bacteria . Results showed presence of the fragment in seven out of the 12 serotypes tested, all of which belonged to biotype A . Two other serotypes belonging to biotype A, all three serotypes belonging to biotype T, two Pasteurella multocida isolates and Escherichia coli did not have the fragment in their genome . Thus the expression of the P . haemolytica biotype A serotype 1-specific agglutinating antigen (PHA1SAA) seems to be due to serotype-specific regulation of protein expression rather than to genetic deletion . Differences in methylation of the PHA1SAA-coding fragment was also noted in DpnI and Sau3AI genomic DNA digests from the various serotypes analyzed by Southern blot . However, no apparent correlation was observed between methylation and PHA1SAA expression . E . coli with a recombinant plasmid containing a homologous genomic fragment derived from P . haemolytica serotype 2 also expressed PHA1SAA. Avian Dis, 1991 Oct-Dec, 35(4), 950 - 4 Genetic variation in resistance of turkeys to experimental challenge with Pasteurella multocida; Sacco RE et al.; Six hundred fifty-five male and female turkeys representing four genetic lines were challenged in 10 experiments over a 3-year period with a field isolate of Pasteurella multocida . Poults were challenged at 45 days of age with 1 ml of an inoculum containing 1.2 x 10(7) bacteria per ml . The lines of turkeys included two randombred control lines (RBC1 and RBC2), a subline (E) of RBC1 selected for increased egg production, and a subline (F) of RBC2 selected for increased 16-week body weight . The number of days from exposure to severe clinical signs or death for Line F (5.8 days) differed significantly from that of Line E (8.2 days), Line RBC1 (8.0 days), and Line RBC2 (8.2 days) . There were no significant differences due to sex of poult for number of days from exposure to severe clinical signs or death . Overall mortality observed was 51.2% . Mortality was highest for Line F (72.1%) and differed significantly from that of the other lines . Mortality among male poults did not differ significantly from mortality among female poults. Avian Dis, 1991 Oct-Dec, 35(4), 761 - 6 Response of broiler chickens to fowl cholera vaccination at 1 to 6 weeks of age; Dick JW et al.; Broiler chickens, in groups of 10, received a single vaccination by the stick-wing route at 1, 2, 3, 4, 5, 6, or 11 weeks of age with live Clemson University strain of Pasteurella multocida . Twenty non-vaccinates kept in isolation served as controls . Cholera serum antibody titers in all chickens were determined by enzyme-linked immunosorbent assay at weekly intervals . Chickens vaccinated once at 1, 2, 3, 4, 5, and 6 weeks, respectively, attained 25.2%, 28.7%, 34.7%, 46.2%, 51.8%, and 64.6% of the titers of those vaccinated once at 11 weeks of age . Variation in antibody response was greatest in chickens vaccinated at 1 or 2 weeks of age . Additionally, chickens vaccinated at 1 or 2 weeks of age showed the longest response time (5 weeks) to reach maximum antibody titers after a single vaccination . When the original vaccinates were revaccinated at 11 weeks of age, all showed a secondary response equal to or greater than that seen in chickens vaccinated once at 11 weeks of age . Age of the chickens at the time of vaccination and antibody titer were positively correlated (r = 0.997) . Overall antibody responses to vaccination were higher and much more uniform as birds increased in age. Am J Vet Res, 1991 Oct, 52(10), 1665 - 71 Pulmonary particle deposition and airway mucociliary clearance in cold-exposed calves; Diesel DA et al.; Effect of cold-induced changes in respiratory pattern on pulmonary particle deposition was investigated in 10 male Holstein calves between the ages of 1 and 3 months . Deposition of intranasally instilled fluorescence-enhanced Pasteurella haemolytica was significantly higher (P less than 0.05) for cold-exposed calves and appears to be caused by the cold-induced respiratory pattern change . Deposition was greater in apical and mediastinal lung lobes, but the reason for this preferential deposition is uncertain . Nasal mucus velocity was measured in 4 nonanesthetized calves at ambient temperature of 2 to 4 C and 16 to 18 C, using tantalum-paraffin oil droplets and serial radiography . Nasal mucus velocity was 24% lower during cold exposure . In addition, the effect of mucosal temperature on tracheal mucus velocity was determined in excised tracheas from 7 calves . A direct relationship existed between mucosal temperature and tracheal mucus velocity within the mucosal temperature range studied (35.0 to 39.5 C) . Tracheal air temperature measurements in calves at ambient temperatures of -10.4 C (n = 4) and 18.5 C (n = 5) indicated that conditioning of inspired air is not complete at the tracheal level during extreme cold exposure . Therefore, cold air may directly influence tracheal mucociliary clearance . It is speculated that cold exposure increases pulmonary deposition of pathogens, while simultaneously decreasing mucociliary clearance of the upper airways, thus predisposing cold-exposed calves to respiratory tract infection. Am J Vet Res, 1991 Oct, 52(10), 1653 - 7 Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from swine; Cote S et al.; Twenty-nine field isolates of porcine Pasteurella multocida were characterized for their capsular and somatic types and were evaluated for their susceptibility to 10 antimicrobial agents . Plasmid DNA-screening experiments were conducted to determine whether a relationship existed between the presence of plasmids and antibiotic resistance . Field isolates of P multocida were susceptible to most of the antimicrobials tested, but all isolates were resistant to clindamycin . Eleven isolates of serogroup D were resistant to 1 or 2 antimicrobial agents . Resistance to sulfonamides and streptomycin was observed in 7 isolates . These isolates contained R plasmids conferring resistance to streptomycin and sulfonamides . The R plasmids belonged to 2 groups, one of 5.6 kilobase and the other of 5.9 kilobase . Restriction endonuclease mapping and DNA hybridization revealed that these R plasmids were related to RSF1010 from Salmonella panama, which also confers resistance to streptomycin and sulfonamides. Am J Vet Res, 1991 Oct, 52(10), 1644 - 8 Electrophoretic profiles of Pasteurella multocida isolates from animals with hemorrhagic septicemia; Johnson RB et al.; We determined that the protein profiles of 14 isolates from animals with hemorrhagic septicemia were relatively homogeneous and could be placed in 2 distinct groups on the basis of their country of origin . Such differences correlated with the serotypic properties of the individual isolates; hemorrhagic septicemia isolates of Asian and North American origin (Carter B) had a major protein band with an apparent molecular mass of 32 kDa, whereas those of African origins (Carter E) had a major protein band with an apparent molecular mass of 37 kDa . The possession of a major 32-kDa protein band appeared to be unique to Carter B isolates, suggesting that electrophoresis may be a useful nonserologic technique for the identification of organisms of this serotype . Other major bands with apparent molecular masses of 27, 45, and 47 kDa were shared by all strains, regardless of their serotype . The lipopolysaccharides were of low molecular mass and relatively uniform from 1 isolate to the next. J Vet Diagn Invest, 1991 Oct, 3(4), 324 - 7 Association of a Pasteurella haemolytica-like organism with enteritis in swine; McLaughlin BG et al.; A Pasteurella haemolytica-like organism was isolated from the intestines of 28 swine with clinical, gross, or microscopic evidence of enteritis . In 15 cases, other known enteric pathogens were also demonstrated, and in 13 cases, no other pathogens were detected . The mean age of affected animals was 44 days . Most of the animals had clinical evidence of diarrhea . Gross enteric lesions were present in 17 of 21 cases . Microscopic lesions were present in 24 of 26 cases . A diffuse or segmental moderate to severe necrotizing enteritis was the most common lesion in cases in which only the Pasteurella haemolytica-like organism was isolated . Biochemical tests gave results consistent with Pasteurella haemolytica, and 5 of 15 isolates met criteria for biotype A . Negative results were found with an indirect haemagglutination procedure for P . haemolytica. J Vet Diagn Invest, 1991 Oct, 3(4), 319 - 23 Distribution of indole-producing urease-negative pasteurellas in animals; Biberstein EL et al.; Three hundred fifty-six animal isolates of indole-positive urease-negative cultures of Pasteurella, which would formerly have been classified as P . multocida, were examined with respect to their relationship to the recently described P . multocida subspecies (ssp.) multocida, septica, and gallicida and P . canis, P . stomatis/Taxon 16, and Pasteurella sp . B . Two hundred sixty-three (73.9%) of the cultures could be identified with one of these taxa, and 93 isolates (26.1%), representing 17 different biotypes, were unassignable . Pasteurella multocida ssp . multocida was the predominant taxon throughout and in most of the 25 animal species from which isolations were made . In dogs, P . canis was the most frequent . Different degrees of host predilection were observed also in P . multocida ssp . septica for cats, P . canis for sheep, and 2 of the unassignable biotypes for cattle and dogs, respectively . Overall, the respiratory tract was the most frequent source of isolates, but a propensity of P . multocida ssp . septica for localization in the central nervous system of cats was noted. J Wildl Dis, 1991 Oct, 27(4), 685 - 7 Taxon 20 (Fam . Pasteurellaceae) infections in European brown hares (Lepus europaeus); Devriese LA et al.; Hemolytic bacteria, phenotypically related to organisms previously identified as Pasteurella haemolytica and tentatively named Taxon 20, were isolated from cases of purulent bronchopneumonia and from conjunctivitis in European brown hares (Lepus europaeus) . The bronchopneumonia, sometimes accompanied by lesions in other organs, occurred without other concomitant disease . The conjunctivitis was found mainly in animals suffering from the European brown hare syndrome. J Wildl Dis, 1991 Oct, 27(4), 543 - 50 Correlations of daily activity with avian cholera mortality among wildfowl; Combs SM et al.; We tested the hypothesis that wildfowl activities can influence the risk of avian cholera (Pasteurella multocida infection) for susceptible birds at Centerville, Humboldt County, California (USA) . Avian cholera mortality characteristics from past epizootics were correlated with variations in flock size, habitat use and 11 feeding and nonfeeding behaviors among six empirically defined groups of wildfowl: American coots (Fulica americana), tundra swans (Cygnus columbianus), American wigeon (Anas americana), northern pintails (A . acuta), northern shovelers (A . clypeata)/mallards (A . platyrhynchos), and teal (A . discors, A . crecca, A . cyanoptera) . The position of these wildfowl groups in past mortality sequences was directly correlated with mean flock size, time spent on land, and time spent grazing on land or in shallow water . We propose that variations in bird density, habitat use and frequency of grazing may serve as predisposing factors to avian cholera among wildfowl. Lab Anim, 1991 Oct, 25(4), 337 - 41 Pathogenicity of Pasteurella multocida A:3 in Flemish giant and New Zealand white rabbits; Dillehay DL et al.; Pasteurella multocida A:3 was isolated during an outbreak of pasteurellosis in Flemish Giant (FG) rabbits . Since New Zealand White (NZW) rabbits housed in the same room were not as severely affected as FG rabbits, experimental inoculation was undertaken to determine if FG rabbits were more susceptible than NZW rabbits to pasteurellosis induced by this isolate . Rabbits of each breed were inoculated with P . multocida A:3 and observed for 3 weeks . Four of 5 FG rabbits developed severe clinical disease on days 6, 9, 12 and 14 after inoculation; whereas, the one affected NZW rabbit became ill 14 days after inoculation . All rabbits with clinical disease developed fibrinosuppurative pleuritis, pyothorax and pneumonia which was more severe in FG than NZW rabbits . At necropsy, P . multocida A:3 was isolated from multiple sites of the diseased rabbits . No significant difference (P = 0.099) in the prevalence of lesions between the two breeds was found; however, the score of pneumonia and pleuritis was 3 times greater in FG rabbits than NZW rabbits. Res Commun Chem Pathol Pharmacol, 1991 Oct, 74(1), 121 - 4 Exposure of sheep to Pasteurella haemolytica alters ex vivo pulmonary vascular smooth muscle alpha adrenergic responses: role of vascular endothelium; Weekley LB et al.; Sheep were exposed to a live- vaccine derived strain of Pasteurella haemolytica (10(5) colony forming units/sheep, i.m.) and euthanized 3 days later . Pulmonary artery and vein ex vivo responses to cumulative doses of methoxamine were determined . In some experiments endothelium was removed . In the pulmonary artery, removal of the endothelium significantly impairs the potency of methoxamine as a contractile agent in control sheep . Also, in sheep exposed to P . haemolytica removal of the endothelium ex vivo impairs the efficacy of methoxamine as a contractile agent . In the pulmonary vein, removal of the endothelium significantly increases the maximum contractile response obtained in control sheep . Conversly, in the pulmonary vein from P . haemolytica exposed sheep, removal of the endothelium reduces the efficacy of methoxamine . These experiments suggest that vaccination with live P . haemolytica impairs pulmonary vascular alpha adrenergic responses . Such impairments may contribute to development of pulmonary edema and congestion during stressful periods such as post-vaccination. Lab Anim Sci, 1991 Oct, 41(5), 423 - 6 Partial characterization of plasmids from rabbit isolates of Pasteurella multocida; Gunther R et al.; Plasmids have not been reported for isolates of Pasteurella multocida from rabbits . We assayed 28 isolates of rabbit P . multocida for plasmids and sought to determine whether or not plasmid presence correlated with clinical or pathologic findings, serotype, toxin production, possession of pili, or biochemical characteristics . Fourteen isolates bore a single 1.6 Md (covalently closed circular form in 0.7% agarose gels) plasmid . An additional isolate had two plasmids which migrated as a closely-spaced doublet, centered around 1.6 Md . Eleven isolates appeared to have identical plasmids, according to Hae III and Hinf I digests . The apparent linear size of this common plasmid in 2% agarose gels was 2.1 Md, as calculated from the sums of the sizes of Hae III or Hinf I digestion fragments . Linearization of the common plasmid with Msp I produced an apparent size of 2.5 Md in 0.7% agarose gels . No correlations between presence of the common plasmid and somatic serotype, toxigenicity, presence of pili, antimicrobial resistance, selected biochemical characteristics, anatomic site from which the bacteria were cultured, or disease status of the host were found. Lab Anim Sci, 1991 Oct, 41(5), 419 - 22 Screening rabbit colonies for antibodies to Pasteurella multocida by an ELISA; Zaoutis TE et al.; Rabbit serum samples from eleven different research facilities were evaluated for the presence of immunoglobulin G against Pasteurella multocida by using an enzyme-linked immunosorbent assay (ELISA) . Each facility which submitted serum samples also provided a brief history of each rabbit colony tested . Rabbits from colonies reported to have endemic P . multocida or of undetermined status had 83 (58.9%) of 141 rabbits that were positive . Colonies reported to be free from P . multocida had 110 (92.4%) of 119 rabbits that were negative by ELISA . The ELISA test described here showed a high degree of agreement (92-94%) with two other P . multocida ELISAs at different diagnostic facilities . This study confirms that an ELISA testing for serum antibodies against the P . multocida is a reliable diagnostic tool to screen colonies for P . multocida. Exp Lung Res, 1991 Sep-Oct, 17(5), 939 - 57 Expression and kinetics of induced procoagulant activity in bovine pulmonary alveolar macrophages; Car BD et al.; Leukocytes, especially macrophages, are important cellular mediators of fibrin deposition and removal at tissue sites of inflammation . Pulmonary fibrin deposition is a prominent feature of bovine acute lung injury; therefore, we studied the resting and stimulated procoagulant responses of bovine pulmonary alveolar macrophages (PAM) and peripheral blood neutrophils (PMN) . Freshly isolated normal PAM and PMN expressed negligible procoagulant activity . PAM stimulated with endotoxin lipopolysaccharide (LPS), 4 beta-phorbol 12-myristate 13-acetate (PMA) and bovine recombinant interleukin-1 beta (rBIL-1 beta) exhibited protein synthesis- and dose-dependent enhancement of procoagulant activity in 8-h cultures . Bovine recombinant granulocyte macrophage-colony stimulating factor (rBGM-CSF) and recombinant human gamma-interferon (rHIFN-gamma) did not induce procoagulant activity . The kinetics of LPS- and PMA-enhanced PAM procoagulant activity differed: LPS-induced enhancement developed earlier and more rapidly than PMA-induced enhancement . Pasteurella haemolytica LPS was more potent than Escherichia coli LPS in enhancing PAM procoagulant activity, while dexamethasone decreased both baseline and LPS- or PMA-stimulated activity by approximately 50% . PAM procoagulant activity resulted from tissue factor expression . Bovine PMN produced negligible procoagulant activity when stimulated, and are thus unlikely to be major contributors to procoagulant activity in bovine lung . Activity inhibitory to bovine tissue factor was present in both calf and adult sera, and was partly dependent on the presence of factor X for activity . Rapid induction of bovine PAM procoagulant activity by inflammatory mediators, and subsequent resistance to degradation, may thus combine to promote an alveolar microenvironment permissive to fibrin deposition in bovine acute lung injury. Br Vet J, 1991 Sep-Oct, 147(5), 437 - 43 Evaluation of combined Pasteurella vaccines in control of sheep pneumonia; Chandrasekaran S et al.; The effectiveness of an oil adjuvant vaccine (OAV) incorporating locally isolated strains of Pasteurella haemolytica type 7 and Pasteurella multocida types A and D was compared with that of Carovax (Wellcome Laboratories) in imported cross-bred lambs . The criterion of efficacy was the ability of the vaccines to reduce the extent of pneumonic lesions in vaccinated as against unvaccinated control lambs . The OAV produced at this Institute significantly reduced the lung lesions at P less than 0.05 level compared with its control group when challenged with P . haemolytica alone . However, the vaccine was unsatisfactory against P . multocida or combined P . multocida P . haemolytica challenge . Carovax did not produce any significant reduction in the lung lesions caused by P . haemolytica and/or P . multocida. Br Vet J, 1991 Sep-Oct, 147(5), 413 - 20 A field investigation of subclinical mastitis in sheep in southern England; Watkins GH et al.; The prevalence, aetiology and epidemiological features of subclinical mastitis were investigated in 358 lowland ewes in seven flocks in southern England . Milk samples (2092) were collected at 3-weekly intervals; those which were both bacteriologically and Whiteside test positive were deemed to have originated from glands with subclinical mastitis . The period prevalence of subclinical mastitis was 11.7% and the prevalence remained relatively constant over the course of lactation (5.5-7.0%) . The predominant bacterial isolates from 48 glands with subclinical mastitis were streptococci (42%), coagulase-negative staphylococci (33%), Pasteurella haemolytica (17%) and Staphylococcus aureus (8%) . Coagulase-negative staphylococci were the predominant isolates (53%) from samples which did not show a positive Whiteside test result . The prevalence of subclinical mastitis increased with age of ewe but was not influenced by the presence of teat lesions . There was a significant association between the development of clinical mastitis (26 glands) and antecedent subclinical mastitis caused by the same organism (10 glands). Infect Dis Clin North Am, 1991 Sep, 5(3), 663 - 80 Infections resulting from animal bites; Weber DJ et al.; Animal bites are a major public health problem . This article reviews the epidemiology and treatment of animal bites . The epidemiology, clinical presentation, and treatment of infections caused by Pasteurella multocida and Capnocytophaga canimorsus (DF-2) are reviewed in detail. Berl Munch Tierarztl Wochenschr, 1991 Sep 1, 104(9), 298 - 303 {Pasteurella multocida as the cause of disease outbreaks in commercial poultry flocks}; Hinz KH et al.; Six cases of fowl cholera in growing turkeys and 3 in adult breeder chickens of the broiler type as well as one case each of a Pasteurella (P.) multocida-associated disease in ducklings and goslings were described in consideration of own laboratory findings and available informations of the case history . Furthermore a report is given on a treatment strategy successfully used in turkeys with highly acute fowl cholera . All the P . multocida strains isolated culturally could be assigned to the subspecies multocida . In one case Bordetella avium, Salmonella (S.) arizonae and S . hadar were additionally cultured form part of turkeys submitted . P . multocida and Moraxella (Pasteurella) anatipestifer could be determined as the causative agents of the disease of ducklings and goslings . P . multocida strains from turkeys were identified serologically as serovars A:3.4 (3x), F:3.4 (2x) and A:3 (1x); those from the breeder chickens as A:3 (3x); and one each from ducklings and goslings as F:3.4 and -:3 . (uncapsulated) . No death occurred in turkeys with clinical signs of a highly acute fowl cholera if the treatment of the affected birds was started with an intravenous injection of sulfadimethoxine and continued with a combination of sulfachlorpyridazine (SCP) and trimethoprim (TMP) given in the drinking water for 5 days . However relapse occurred 2-3 days after withdrawal of the drug, although the therapy was clinically highly effective . The recurrence of the disease could be prevented reliably if the turkeys were vaccinated with an effective oil-based bacterin and subsequently treated with the SCP-TMP combination given in drinking water over a 12 day period. Am J Vet Res, 1991 Sep, 52(9), 1507 - 11 Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils; Harmon BG et al.; A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays . The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University) . All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy . Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate. J Bacteriol, 1991 Sep, 173(18), 5597 - 603 Cloning, nucleotide sequence, and expression of the Pasteurella haemolytica A1 glycoprotease gene; Abdullah KM et al.; Pasteurella haemolytica serotype A1 secretes a glycoprotease which is specific for O-sialoglycoproteins such as glycophorin A . The gene encoding the glycoprotease enzyme has been cloned in the recombinant plasmid pH1, and its nucleotide sequence has been determined . The gene (designated gcp) codes for a protein of 35.2 kDa, and an active enzyme protein of this molecular mass can be observed in Escherichia coli clones carrying pPH1 . In vivo labeling of plasmid-encoded proteins in E . coli maxicells demonstrated the expression of a 35-kDa protein from pPH1 . The amino-terminal sequence of the heterologously expressed protein corresponds to that predicted from the nucleotide sequence . The glycoprotease is a neutral metalloprotease, and the predicted amino acid sequence of the glycoprotease contains a putative zinc-binding site . The gene shows no significant homology with the genes for other proteases of procaryotic or eucaryotic origin . However, there is substantial homology between gcp and an E . coli gene, orfX, whose product is believed to function in the regulation of macromolecule biosynthesis. Infect Immun, 1991 Sep, 59(9), 3126 - 33 Activation of bovine neutrophils by partially purified Pasteurella haemolytica leukotoxin; Czuprynski CJ et al.; In this study we developed a new method for the partial purification of Pasteurella haemolytica leukotoxin by size-exclusion high-performance liquid chromatography . The partially purified leukotoxin had a molecular weight of 104,000, as estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reacted on an immunoblot with an antileukotoxin monoclonal antibody . As expected, high concentrations of the leukotoxin were inhibitory or lethal to bovine neutrophils . Incubation of bovine neutrophils with diluted leukotoxin, however, resulted in significant neutrophil activation that was comparable in magnitude to that obtained with standard activating agents such as opsonized zymosan or zymosan-activated serum . Dilute leukotoxin (1:128 to 1:8,192 dilutions) stimulated an oxidative burst (luminol-dependent chemiluminescence) by bovine neutrophils that was comparable in magnitude to that obtained with opsonized zymosan . Preincubation with leukotoxin did not significantly prime the neutrophils for an enhanced oxidative burst when they were then exposed to opsonized zymosan as a second stimulus . Dilute leukotoxin (1:100 to 1:1,000 dilutions) also stimulated cytoskeletal alterations in bovine neutrophils, as measured by a significant shape change response . Preferential release of secondary granule constituents (lactoferrin) occurred when neutrophils were incubated with 1:100 to 1:500 dilutions of leukotoxin . Significant release of primary granules, as measured by beta-glucosaminidase activity, was not observed except at low dilutions (1:20) of leukotoxin that resulted in significant release of cytosolic constituents (i.e., lactate dehydrogenase activity) . The neutrophil-activating activity of the leukotoxin was heat labile, unaffected by polymyxin B, and abrogated by a leukotoxin-neutralizing monoclonal antibody . These data indicate that P . haemolytica leukotoxin, like the closely related Escherichia coli hemolysin, is a potent neutrophil-activating agent . Leukotoxin-stimulated release of neutrophil oxygen intermediates and granule constituents may contribute to the intense inflammation that characterizes bovine pulmonary pasteurellosis. Infect Immun, 1991 Sep, 59(9), 3026 - 32 Nucleotide sequence of the hemolysin I gene from Actinobacillus pleuropneumoniae; Frey J et al.; The DNA sequence of the gene encoding the structural protein of hemolysin I (HlyI) of Actinobacillus pleuropneumoniae serotype 1 strain 4074 was analyzed . The nucleotide sequence shows a 3,072-bp reading frame encoding a protein of 1,023 amino acids with a calculated molecular size of 110.1 kDa . This corresponds to the HlyI protein, which has an apparent molecular size on sodium dodecyl sulfate gels of 105 kDa . The structure of the protein derived from the DNA sequence shows three hydrophobic regions in the N-terminal part of the protein, 13 glycine-rich domains in the second half of the protein, and a hydrophilic C-terminal area, all of which are typical of the cytotoxins of the RTX (repeats in the structural toxin) toxin family . The derived amino acid sequence of HlyI shows 42% homology with the hemolysin of A . pleuropneumoniae serotype 5, 41% homology with the leukotoxin of Pasteurella haemolytica, and 56% homology with the Escherichia coli alpha-hemolysin . The 13 glycine-rich repeats and three hydrophobic areas of the HlyI sequence show more similarity to the E . coli alpha-hemolysin than to either the A . pleuropneumoniae serotype 5 hemolysin or the leukotoxin (while the last two are more similar to each other) . Two types of RTX hemolysins therefore seem to be present in A . pleuropneumoniae, one (HlyI) resembling the alpha-hemolysin and a second more closely related to the leukotoxin . Ca(2+)-binding experiments using HlyI and recombinant A . pleuropneumoniae prohemolysin (HlyIA) that was produced in E . coli shows that HlyI binds 45Ca2+, probably because of the 13 glycine-rich repeated domains . Activation of the prohemolysin is not required for Ca2+ binding. Agents Actions, 1991 Sep, 34(1-2), 197 - 9 An in vitro model system to evaluate pulmonary macrophage, endothelial cell, and neutrophil interactions; Sharma SD et al.; Pasteurella haemolytica, the cause of fibrinous pleuropneumonia in cattle, produces extensive microvascular endothelial cell (EC) damage . We have developed an in vitro model system to study the inflammatory process of this disease involving the interaction of pulmonary alveolar macrophages (AM), neutrophils (PMN), and EC . Bovine EC are grown to confluency in 24 well tissue culture plates . To mimic the vascular component, 10(6) PMN are later added to the EC monolayers . Bovine AM are plated onto millicell inserts and placed into the wells containing EC and PMN . The millicell insert serves as a semi-permeable barrier between AM and EC, allowing the exchange of only diffusible material . Preliminary work demonstrates that P . haemolytica stimulated AM resulted in EC damage presumably due to both soluble lipopolysaccharide and AM secreted products. Res Vet Sci, 1991 Sep, 51(2), 203 - 8 Occurrence and diversity of plasmids in ovine isolates of Pasteurella haemolytica; Wood AR et al.; 160 ovine isolates of Pasteurella haemolytica, representing each of the 16 serotypes and also untypable strains, were examined for plasmid content . Plasmid DNA was identified in, and prepared from, strains of serotypes A2, T3, A14 and A16 and also from an untypable strain . The relationship between the plasmids present in the different strains was examined both by restriction fragment profile analysis and by DNA/DNA hybridisation . Both methods gave broadly similar results and showed that each serotype tended to contain either a single plasmid species, or a limited range of species, and that structural similarities could traverse serotype boundaries . None of the plasmid-bearing strains showed any significant level of resistance to a range of antibiotics. Res Vet Sci, 1991 Sep, 51(2), 209 - 14 Protective effect of inactivated bovine herpesvirus-1 in calves experimentally infected with bovine herpesvirus-1 and Pasteurella haemolytica; Jericho KW et al.; The protective effect of an inactivated whole-virion bovine herpesvirus-1 (BHV-1) immunising inoculum, without adjuvant, against viral-bacterial respiratory disease was studied in three experimental treatment groups of five calves each . One group was boosted 14 days after the first vaccination and at this time the second group received their initial inoculation . Seven days later, calves were challenged with BHV-1 in aerosol and four days after this challenge all calves were exposed to Pasteurella haemolytica A1 in aerosol . Among the three groups, differences in rectal temperature responses four days after viral challenge (P less than 0.01) did not relate to protection . However the main response variable, viral-bacterial pneumonia, was reduced in boosted calves (P less than 0.05). Vet Immunol Immunopathol, 1991 Aug, 29(1-2), 57 - 68 Preliminary investigation of the mechanism of inhibition of bovine lymphocyte proliferation by Pasteurella haemolytica A1 leukotoxin; Majury AL et al.; Pasteurella haemolytica A1 leukotoxic culture supernate has been shown to inhibit bovine lymphocyte blastogenesis induced by concanavalin A (Con A), pokeweed mitogen (PWM) and purified protein derivative (PPD) . The various mechanisms by which this inhibition could be overcome were investigated in an effort to determine at which stage of cell activation the leukotoxin exerted its inhibitory effect . For both Con A and PWM stimulated cultures, the addition of partially purified bovine interleukin 1 reduced the leukotoxin-induced inhibition . Recombinant interleukin 2 had a similar effect . Addition of the glycolipid, monosialoganglioside was also able partially to overcome the inhibition. Vet Immunol Immunopathol, 1991 Aug, 29(1-2), 41 - 56 The effect of Pasteurella haemolytica A1 leukotoxic culture supernate on the in vitro proliferative response of bovine lymphocytes; Majury AL et al.; The effect of sublethal concentrations of the Pasteurella haemolytica leukotoxic culture supernate on bovine lymphocyte blastogenesis was investigated . Blastogenesis in cultures stimulated with either concanavalin A (Con A) or pokeweed mitogen (PWM) was inhibited in the presence of the supernate, as was the response to purified protein derivative in lymphocytes from BCG-vaccinated cattle . Partially purified leukotoxin had a similar effect . Pre-incubation of the leukotoxic supernate with a polyclonal rabbit antiserum raised to the immunogenic molecule of recombinant leukotoxin (r LktA) abrogated this effect, implicating leukotoxin as the factor responsible for the inhibition . B cell enriched cultures tended to be more sensitive to leukotoxic effects than did T cell enriched cultures . Although only ruminant cells are susceptible to the lethal effects of P . haemolytica leukotoxin, the toxin did inhibit both Con A- and PWM-induced proliferation of human and dog lymphocytes . As well, at high leukotoxin doses, Con A-stimulated pig lymphocyte proliferation was reduced . Rabbit lymphocytes were not affected by leukotoxin in either Con A- or PWM-stimulated cultures. Dtsch Tierarztl Wochenschr, 1991 Aug, 98(8), 310 - 2 {Detection of neutralizing antibodies against Pasteurella multocida toxin in swine with atrophic rhinitis}; Bechmann G et al.; Blood sera of 1171 pigs, not vaccinated against PAR, were tested for antibodies against P . multocida toxin in a neutralization test with EBL cell cultures . 277 sera were from 18 herds with clinical PAR; 104 of them (37.5%) had neutralizing antibody titres from 1:2 to 1:1024 . No antitoxin was detected in the sera of 866 pigs in 25 PAR nonsuspicious herds . In one nonsuspicious herd, however, 11 of 28 sera were neutralizing in the 1:2 or 1:4 dilution . 30 sows had been vaccinated with inactivated toxigenic P . multocida and/or with the P . multocida toxoid . 21 of these sows had neutralizing sera with titres between 1:8 and 1:4096 . The neutralization test presented can be applied for herd diagnosis of PAR and for demonstration of vaccination effects. Am J Vet Res, 1991 Aug, 52(8), 1245 - 51 Actinobacillus suis-like organisms and evidence of hemolytic strains of Actinobacillus lignieresii in horses; Samitz EM et al.; Thirty-seven local isolates of Actinobacillus suis-like organisms from diseased and clinically normal horses and 1 llama were compared with reference strains of A suis, A lignieresii, A equuli, A capsulatus, A hominis, A (Pasteurella) ureae, and equine A suis-like organisms (ASLO) previously described in literature . Comparison was by cultural characteristics, carbohydrate fermentation, enzyme profiles, and whole-cell protein polyacrylamide gel electrophoresis . Carbohydrate fermentation, determined by API-CH gallery, divided 36 equine ASLO isolates into 6 API-CH biotypes . The llama isolate was an additional distinct biotype . The biochemical comparisons between A suis and ASLO did not reveal remarkable and consistent differences . Enzyme analysis revealed 5 API-ZYM biotypes, one of which included the same strains as one of the API-CH biotypes and consisted in both instances of 4 esculin-negative ASLO cultures and the reference strain of A lignieresii . We conclude that the 4 strains were hemolytic variants of A lignieresii . Protein electrophoresis disclosed 15 banding patterns, 10 of which represented equine ASLO strains . The reference strains of A suis shared the pattern predominant among equine ASLO . Four of the remaining reference strains of Actinobacillus species each had a unique profile, whereas the type strain of A capsulatus and the llama isolate had similar profiles . The groupings of cultures resulting from the different testing methods had little relation to each other and to the anatomic source of the strains except the strains comprising API-CH biotype II, which originated in the equine respiratory tract, and the A lignieressi cluster. Am J Vet Res, 1991 Aug, 52(8), 1214 - 20 Comparison of four immune variables and pulmonary lesions of goats with intrapulmonary exposure and subsequent intrathoracic challenge exposure with Pasteurella haemolytica; Purdy CW et al.; A comparison of immune variables following lung sensitization with live Pasteurella haemolytica serotype 1 (Ph1)-impregnated agar beads was done in 2 separate trials . The Ph1 immune variables studied were blood bactericidal activity, serum bacteriolysis, total classical complement, and indirect hemagglutination antibody . Each trial had 16 male weanling goats: 6 controls and 10 principals . In trial 1, each goat was surgically catheterized through the trachea, then the material was deposited in a bronchus . The controls received only agar beads and the principals received agar beads impregnated with live Ph1 . These goats were studied for 32 days, euthanatized, and necropsied . In trial 2, the controls were each transthoracically injected with agar beads into the left lung and the principals were similarly injected with agar beads impregnated with live Ph1 . These goats were studied for 35 days, then challenge exposed transthoracically by injection of Ph1 in saline solution (1.2 x 10(7) CFU/ml) into the right lung . Four days later, they were euthanatized and necropsied . The volume of lung consolidated tissue was an excellent measure of Ph1 immunity . Principal goats generated solid protective immunity to subsequent challenge exposure because minimal or no lung consolidation was observed, whereas large volumes of lung consolidation were seen in the controls . The principal goats in trial 1 gave a weak serum indirect hemagglutination Ph1 antibody response, which was attributed to the bronchial method of depositing the Ph1 . The corresponding response of the control group remained negative . The Ph1 agar beads (1 x 10(6) CFU in 0.5 ml) protected the bacteria from immediate phagocytosis and lysis as indicated by the induced pneumonic deaths of 2 principals 5 days later.(ABSTRACT TRUNCATED AT 250 WORDS) Poult Sci, 1991 Aug, 70(8), 1704 - 8 A retrospective analysis on the epizootiological aspects of outbreaks of Pasteurella anatipestifer infection in turkeys in Minnesota; Charles SD et al.; The possible risk factors associated with outbreaks of Pasteurella anatipestifer infection in turkeys were analyzed to study the epizootiology of the disease . The data for the study was obtained from flocks affected and unaffected with Pasteurella infection . The results of the analysis suggested that overcrowding, preexisting viral infections, increased activity of wild birds on the farm, and shorter down time were possible factors that initiate the occurrence of the disease in turkey flocks . The statistical models used in the analysis predicted correctly 80% of the unaffected flocks (8 out of 10 flocks), and 95% of the affected flocks (13 out of 14 flocks) . The overall correct prediction was 88% (21 out of 24 flocks) . Fish meal and meat and bone meal, which are integral components of turkey feed, were analyzed for the possible presence of P . anatipestifer . Its presence in a sample of fish meal was demonstrated. J Bacteriol, 1991 Aug, 173(16), 5151 - 8 The Actinobacillus pleuropneumoniae hemolysin determinant: unlinked appCA and appBD loci flanked by pseudogenes; Chang YF et al.; The appBD genes encoding the secretion functions for the 110-kDa RTX hemolysin of Actinobacillus pleuropneumoniae have been cloned and sequenced . Unlike analogous genes from other RTX determinants, the appBD genes do not lie immediately downstream from the hemolysin structural gene, appA . Although isolated from a diverse group of gram-negative organisms, the appBD genes and the characterized RTX BD genes from other organisms all exhibit a high degree of homology at both the DNA and predicted amino acid sequence levels . Analysis of the DNA sequences 3' to appA and 5' to appB suggests that these regions harbor remnant RTX B and A pseudogenes, respectively . Although the appA gene is most similar to the lktA gene from Pasteurella haemolytica (Y . F . Chang, R . Young, and D . K . Struck, DNA 8:635-647, 1989), the RTX A pseudogene upstream from appB most closely resembles the hlyB gene from Escherichia coli, suggesting that the appCA and appBD operons were derived from different ancestral RTX determinants. Mol Gen Mikrobiol Virusol, 1991 Aug, (8), 29 - 32 {Isolation and certain properties of the dermonecrotic toxin from Pasteurella multocida}; Kalmykova LI et al.; The procedure for isolation and purification of Pasteurella multocida serovariant D toxin has been described . It includes the three steps of protein precipitation from cultural filtrates by 70% ammonium sulfate, chromatography of the concentrated material on Ultragel AcA44 gel-filtration on Sephracryl S-200 . The proposed technique permits one the 155-fold purification of the preparation with 32.6% yield estimated by biological activity . The obtained purified preparation is homogeneous in polyacrylamide gel electrophoresis . The immunological methods also confirm the homogeneity of the preparation . The minimal dermonecrotic dose for guinea pigs of the purified 120 kDa toxin is 78 ng and LD50 for mice is 280 ng . Pasteurella multocida toxin is found to be a thermolabile protein sensitive to trypsin, glutaraldehyde and formaldehyde treatments. J Comp Pathol, 1991 Aug, 105(2), 157 - 66 Immune responses of lambs experimentally infected with bovine respiratory syncytial virus and Pasteurella haemolytica; Sharma R et al.; The immune responses of lambs experimentally infected with bovine respiratory syncytial virus (RSV) and Pasteurella haemolytica were compared with lambs infected with bovine RSV or Pasteurella haemolytica alone . Superinfection with P . haemolytica aggravated the reduction in the number of CD5+, CD4+ and LCA p220+ (B) lymphocytes caused by bovine RSV, but it had no effect on the neutralizing antibodies against P . haemolytica cytotoxin . Serum samples obtained from lambs experimentally infected with bovine RSV and P . haemolytica had significantly lower amounts of neutralizing antibodies to bovine RSV than those obtained from lambs infected with bovine RSV alone. Am J Vet Res, 1991 Aug, 52(8), 1345 - 9 Molecular epidemiology of Pasteurella multocida in turkeys; Carpenter TE et al.; Pasteurella multocida isolated from turkeys during an outbreak of fowl cholera was characterized by serotype and heterogeneity of genes encoding rRNA (ribotype) to investigate the epidemiology of the organism . Isolates were collected between October 1985 and July 1986 . The M9 or Clemson University fowl cholera vaccine-like strain was detected in 17% of the flocks with fowl cholera . One particular strain, isolated only from breeder flocks, was recovered from 7 of the 10 breeder flocks examined in this study . Intracompany transmission appeared to be common, implying a failure in biosecurity . Circumstantial evidence indicated that in the field; the incubation period of P multocida in a turkey flock may be between 2 to 7 weeks . Wildlife did not appear to be an important reservoir of P multocida for turkeys during this study period . Ribotyping results tended to discount several of the possible interflock transmissions, as suggested by examination of serotyping results alone; however, serotyping in combination with ribotyping proved helpful in understanding the epidemiology of P multocida in turkeys. J Comp Pathol, 1991 Aug, 105(2), 203 - 11 Clinical chemical constituents in relation to liver amyloidosis in serum-producing horses; Abdelkader SV et al.; Serum activities of gamma-glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AST), and concentrations of total bilirubin and total bile acids were screened during a 5 year period in 27 horses used for production of hyperimmune serum . The horses investigated were regularly immunized with live cultures of the endotoxin-releasing bacteria Escherichia coli or Pasteurella multocida, the individual animals having undergone such treatment for periods varying from 2 weeks to 10 years . In a majority of the horses, GGT-activity had increased within 6 to 7 years of first having undergone immunization . Constantly high values seemed to co-incide with the presence of advanced liver amyloidosis, as demonstrated by histopathological examination after slaughter . The AP activity was also increased but only moderately compared with GGT . Individual values more than 10-fold greater than the upper reference limit were recorded for GGT, while the highest AP values were less than double the upper reference limit . Activity of AST and bilirubin concentrations remained unaffected, whereas the concentration of total bile acids rose after 6 to 7 years of immunization compared to the baseline value . It is concluded that the determination of serum activities of GGT may serve as a practical routine test for the evaluation of liver amyloidosis status in serum horses. Mutat Res, 1991 Jul, 263(3), 159 - 63 Pasteurella haemolytica is highly sensitive to ultraviolet irradiation; Lo RY et al.; The response of Pasteurella haemolytica to ultraviolet irradiation was determined . The results for survival show that P . haemolytica is very sensitive to UV-irradiation . This UV-sensitivity is similar to E . coli strains defective in UV repair mechanism(s) . Analysis of the distribution of TCA insoluble versus TCA soluble {3H}thymine dimers in UV-irradiated DNA of P . haemolytica during a 2-h post-irradiation period indicates that the bacterium is deficient in an excision-repair system . These data suggest that P . haemolytica lacks some of the important mechanisms to repair UV-induced damage. Avian Dis, 1991 Jul-Sep, 35(3), 618 - 20 Pasteurellosis in bobwhite quail; Bermudez AJ et al.; A flock of 5000 six-week-old bobwhite quails (Colinus virginianus) experienced high mortality (52%) over a 2-day period . Mortality was 99% within a 6-day period . Clinical signs were depression followed shortly by death . Gross lesions observed in dead quails were congested lungs and, in a few cases, mottled livers . Histopathologic examination revealed severe, diffuse, heterophilic interstitial pneumonia and multifocal areas of hepatic and splenic necrosis with numerous intracellular and extracellular short bacterial rods . Serotype 3, 4, 15, 16, Pasteurella multocida, isolated from the index case, caused 50% mortality in experimentally inoculated bobwhite quails within 9 to 24 hours . This report indicates that pasteurellosis can cause peracute disease in bobwhite quails with very high mortality. Vet Pathol, 1991 Jul, 28(4), 275 - 85 Alterations in pulmonary morphology and peripheral coagulation profiles caused by intratracheal inoculation of live and ultraviolet light-killed Pasteurella haemolytica A1 in calves; Whiteley LO et al.; Eighteen male Holstein calves were divided into groups of three and inoculated intratracheally with 5 x 10(9) logarithmic phase or ultraviolet light-killed Pasteurella haemolytica biotype A serotype 1 . Serial coagulation profiles were done on one calf from each group during the first 24 hours after inoculation . One calf from each group was necropsied at 4, 12, and 24 hours after inoculation and lesions were characterized with light and transmission electron microscopy . We found that 1) the pulmonary intravascular macrophage may have an important role in the early intravascular inflammatory events; 2) there was morphologic evidence for local initiation of the coagulation cascade in the lung early in the disease process but it was not a consumptive process; and 3) killed-bacteria were capable of causing fibrin exudation, platelet aggregation and alveolar epithelial damage similar to live bacteria, but the degenerative changes in neutrophils, endothelial cells and intravascular fibrin formation that occur with live bacteria were not seen. Vet Pathol, 1991 Jul, 28(4), 267 - 74 Colonization of the pharyngeal tonsil and respiratory tract of the gnotobiotic pig by a toxigenic strain of Pasteurella multocida type D; Ackermann MR et al.; Seven-day-old gnotobiotic pigs were inoculated intranasally with Pasteurella multocida and euthanatized 2, 5, 9, and 14 days after inoculation . Tissues from the oropharynx and respiratory tract of pigs were cultured quantitatively and analyzed microscopically . Pigs remained afebrile and alert, except one that died of acute fibrinopurulent pneumonia . Pasteurella multocida was isolated in greatest numbers from the pharyngeal tonsils, but only in low numbers from turbinate, trachea, lung, spleen, and liver . Significant histologic changes were limited to the tonsil . Infected pigs developed mild tonsillitis with lymphocytic hyperplasia, and accumulation of cell debris and bacteria in crypts . Capsular antigens of P . multocida, identified on tissue sections with rabbit anti-capsular polysaccharide antibody and immunocytochemical reagents, were confined to the crypt lumen . Ultrastructurally, bacteria were free within crypt material or within phagosomes of macrophages or neutrophils . In a second experiment, 5-day-old pigs were infected with Streptococcus suis type 2, followed by toxigenic Pasteurella multocida at 7 days of age; one pig died of streptococcal septicemia . Pigs developed a mild tonsillitis, and both bacteria were cultured from the tonsillar crypts for up to 14 days after infection . These studies show that a toxigenic strain of Pasteurella multocida, which is a causative agent of atrophic rhinitis, can colonize the tonsil and respiratory tract of gnotobiotic pigs for up to 14 days . In addition, colonization can occur concurrently with Streptococcus suis type 2. Clin Ther, 1991 Jul-Aug, 13(4), 457 - 9 Treatment of posttraumatic osteitis with intravenous ofloxacin; Seibold R et al.; The subjects were 25 patients with osteomyelitis (n = 17) or other bone or joint infections, scheduled for surgical procedures, including debridement, sequestrectomy, and bone resection and reconstruction . Staphylococcus aureus was isolated in 22 patients, Staphylococcus epidermidis in one, Streptococcus haemolyticus in one, Pseudomonas aeruginosa in one, and a Pasteurella species in one . During surgery and for a mean of four days after surgery, each patient received 200 mg of ofloxacin intravenously twice daily (one patient received 300 mg and another received 400 mg twice daily) . The patients were then given 200 mg of ofloxacin orally twice daily until the wound was healed (after a mean of 18 days) . The wound was healed in all patients and no cases of reinfection occurred . It is concluded that intravenous ofloxacin given perioperatively may be more effective than oral ofloxacin in the management of osteomyelitis. Zentralbl Veterinarmed B, 1991 Jul, 38(5), 345 - 52 Characterization of toxin from different strains of Pasteurella multocida serotype A and D; Frandsen PL et al.; Chromosomal DNA from 13 different selected Pasteurella multocida spp . multocida strains of serotypes A and D were isolated and compared . All 10 toxigenic strains were recognized by a DNA probe which included the toxA gene coding for the Pasteurella multocida toxin (PMT) . None of the three nontoxigenic strains reacted with the DNA probe . Toxin from the 10 toxigenic strains were isolated and compared . All were found to possess the biological characteristics previously described for the PMT isolated from P . multocida ssp . multocida NCTC 12178, including molecular mass of approx . 143 kDa and reactivity with a series of monoclonal antibodies . Toxin prepared from different toxigenic strains could not be differentiated immunologically by tandem crossed immunoelectrophoresis, Toxin, which was affinity purified from four of the strains and subsequently inactivated by formaldehyde, was cross-protective when used for vaccination of mice before challenge with PMT . It is concluded that the toxin from toxigenic strains of P . multocida ssp . multocida must be very similar, if not identical. Lab Anim, 1991 Jul, 25(3), 236 - 41 Naturally acquired Pasteurella multocida subsp . multocida infection in a closed colony of rabbits: characteristics of isolates; Digiacomo RF et al.; Twelve litters, comprising 41 rabbits aged 35 to 60 days old, in a closed university colony, were monitored for acquisition of nasal Pasteurella multocida subsp . multocida infection . Isolates from 11 infected rabbits were characterized by colonial morphology, capsular type, biotype and antibiotic resistance . Selected isolates were further characterized by somatic antigen typing . Two major strains of P . multocida subsp . multocida were detected in the colony . One strain had mucoid colonies, fermented few carbohydrates and was serotype A:5, whereas, the other strain had smooth iridescent colonies, non-typeable capsular antigen, type 3 somatic antigen and fermented more than twice as many carbohydrates. J Wildl Dis, 1991 Jul, 27(3), 367 - 95 Epizootiology of avian cholera in wildfowl; Botzler RG; Pasteurella multocida, the cause of avian cholera, has naturally infected over 100 species of free-living birds . Among wild birds, avian cholera has its greatest impact on North American wildfowl . Epizootics usually are explosive in onset and may involve thousands of birds . The disease has been reported in every month of the year among wildfowl . Disproportionate mortality, with some species suffering proportionately greater mortality than others, has been a common feature of this disease . Presence of animal organic matter plays a significant role in the survival of P . multocida . There are conflicting reports or a lack of information on the role of host sex, age, body size, other physical features, genetic variation or behavioral differences, as predisposing factors to infection by P . multocida . There also are ambiguities on the relationship between season, precipitation, temperature, nutritional stress, water quality, other microorganisms, and environmental contaminants, and the occurrence of avian cholera in wildfowl . Two competing hypotheses for the year-round reservoir of wildfowl strains of P . multocida are ambient soil or water of enzootic sites, and carrier animals; most current evidence favors the role of carrier animals . Transmission most likely occurs by ingestion of contaminated water, inhalation of bacteria-rich aerosols, or both . While many techniques have been proposed to prevent or control avian cholera, none have been rigorously tested to determine their effectiveness. Br Vet J, 1991 Jul-Aug, 147(4), 352 - 5 Isolation of Pasteurella haemolytica from the nasal cavity of goats; Jasni S et al.; Twenty transport-stressed goats were divided into two groups . The first group was further stressed with steroid . Pasteurella haemolytica was found at various sites in the nasal cavity of goats in this group as early as 2 weeks post-transportation . The successful isolations continued consistently with more goats having pure growth of P . haemolytica at later stages . Mild catarrh rhinitis, loss of epithelial cilia and erosions were the main lesions observed in the nasal cavity . Goats in the second group that were not given steroid injections had inconsistent bacterial isolation and less severe pathological lesions. Can J Vet Res, 1991 Jul, 55(3), 234 - 8 Naturally acquired Pasteurella multocida infection in rabbits: clinicopathological aspects; DiGiacomo RF et al.; A cohort of 41 New Zealand White rabbits, 35 to 60 days old, from twelve litters were followed for twelve weeks for development of pasteurellosis . Eleven of 19 rabbits in five litters acquired Pasteurella multocida infection . The incubation period was difficult to determine as P . multocida infection was detected both before and after the onset of rhinitis . The response of rabbits to infection varied from subclinical infection to death from systemic pasteurellosis . Atrophy of the maxilloturbinates of the nares was detected in rabbits with chronic rhinitis associated with P . multocida infection. Can J Vet Res, 1991 Jul, 55(3), 224 - 8 Atrophic rhinitis caused by Pasteurella multocida type D: morphometric analysis; Martineau-Doize B et al.; In order to study the distribution and the extent of atrophy caused by Pasteurella multocida in the nasal conchae, experimental piglets were injected intramuscularly at seven days of age with either two or four 50% mouse lethal doses per kg body weight of P . multocida type D dermonecrotoxin . Experimental and control piglets were killed four, six and ten days postinjection . Serial transverse paraffin embedded sections of the noses were cut throughout the entire length of the nasal conchae . The area of the nasal ventral conchae was measured and the morphometric index of the nasal cavity was calculated . It was observed that P . multocida type D dermonecrotoxin induced severe atrophy of the nasal ventral conchae . This atrophy was present along the entire conchae . However, it was most severe at the level of the first and second premolar teeth. J Infect, 1991 Jul, 23(1), 65 - 7 Pasteurella haemolytica endocarditis; Yaneza AL et al.; Although human infections with bacteraemia due to Pasteurella multocida are not uncommon, endocarditis associated with P . haemolytica is rare . We describe such a case in which the patient died despite treatment with apparently appropriate antimicrobial agents. J Clin Microbiol, 1991 Jul, 29(7), 1328 - 32 Detection and enumeration of toxin-producing Pasteurella multocida with a colony-blot assay; Magyar T et al.; Colonies of toxin-producing Pasteurella multocida were detected with peroxidase-labeled monoclonal antibodies by a membrane assay . Examination of the specificity of the assay with 29 P . multocida cultures representing various geographic origins, hosts, and serotypes indicated that the test was specific for toxin-producing strains . No cross-reactions were observed with Bordetella species that can be associated with P . multocida in producing diseases in animals . A single membrane could be used to assay several isolated strains for toxin production or to enumerate toxin-producing colonies in mixed cultures . Toxin-producing P . multocida colonies were detected in primary cultures; hence, the assay appears to have good potential for widespread application with clinical samples. J Laryngol Otol, 1991 Jul, 105(7), 571 - 2 Meningitis from canine Pasteurella multocida following mastoidectomy; Dammeijer PF et al.; A case of Pasteurella multocida meningitis, following a mastoidectomy is presented . The association of close contact with pets, many of which harbour Pasteurella multocida as part of their normal buccal flora . This case confirms the potential benefit of taking an ear swab prior to mastoid surgery and in seeking an appropriate 'pet' history. Microb Pathog, 1991 Jul, 11(1), 47 - 56 Evidence for non-siderophore-mediated acquisition of transferrin-bound iron by Pasteurella multocida; Ogunnariwo JA et al.; Two clinical isolates of Pasteurella multocida associated with bovine pneumonia were examined for iron acquisition . Both isolates were capable of obtaining iron for growth from bovine but not from human, avian, equine or porcine transferrin . This correlated with specific binding of bovine transferrin by iron-limited cells or isolated membranes . No siderophore was detected in the strains by a general screening assay . In response to iron-limited conditions, a number of high molecular mass iron-regulated outer membrane proteins were produced including an 82 kDa receptor protein which was affinity isolated with biotinylated transferrin . In contrast, avian strains of P . multocida could not use transferrin-bound for growth and did not express either transferrin binding activity or the 82 kDa receptor protein. Nature, 1991 Jun 27, 351(6329), 759 - 61 Activation of Escherichia coli prohaemolysin to the mature toxin by acyl carrier protein-dependent fatty acylation; Issartel JP et al.; Haemolysin secreted by pathogenic Escherichia coli binds to mammalian cell membranes, disrupting cellular activities and lysing cells by pore-formation . It is synthesized as nontoxic prohaemolysin (proHlyA), which is activated intracellularly by a mechanism dependent on the cosynthesized HlyC . Haemolysin is one of a family of membrane-targeted toxins, including the leukotoxins of Pasteurella and Actinobacillus and the bifunctional adenylate cyclase haemolysin of Bordetella pertussis, which require this protoxin activation 1-5 . HlyC alone cannot activate proHlyA, but requires a cytosolic activating factor6 . Here we report the cytosolic activating factor is identical to the acyl carrier protein and that activation to mature toxin is achieved by the transfer of a fatty acyl group from acyl carrier protein to proHlyA . Only acyl carrier protein, not acyl-CoA, can promote HlyC-directed proHlyA acylation, but a range of acyl groups are effective. J Med Microbiol, 1991 Jun, 34(6), 333 - 7 Dermonecrotic toxin production by strains of Pasteurella multocida isolated from man; Donnio PY et al.; Ninety-four clinical isolates of Pasteurella multocida of human origin were tested for dermonecrotic toxin (DNT) production by three methods: dermonecrotic test in guinea-pigs, Vero cell culture cytotoxicity and ELISA . The strains were isolated from patients living in a rural area with widespread intensive pig breeding . Six strains were found to be toxigenic by the three tests . A major protein band of Mr 145 Kda corresponding to DNT on immunoblots was demonstrated in extracts from these strains . All were isolated from respiratory tract (diseases 5, healthy carriage 1) . The difference between isolates from the respiratory tract and isolates from wounds inflicted by pets was statistically significant with regard to DNT production (p less than 0.02) . A possible role of the toxin in pulmonary diseases caused by P . multocida has yet to be established. Chest . 1991 Jun;99(6):1517. Telescoping plugged catheter . An unusual way of diagnosing Pasteurella multocida pneumonia; Ruiz-Santana S et al.; We report a case of Pasteurella multocida pneumonia and its unusual clinical presentation . We also discuss the rarity of its diagnosis by TPC specimens and the delay in both an adequate diagnosis and treatment. J Vet Pharmacol Ther, 1991 Jun, 14(2), 174 - 84 Effects of experimentally induced Pasteurella haemolytica infection in dairy calves on the pharmacokinetics of flumequine; Mevius DJ et al.; The effect of experimental Pasteurella haemolytica infection on the intravenous and intramuscular pharmacokinetics of flumequine was studied in dairy calves . The plasma concentration-time curve of flumequine after intravenous injection of 5 mg/kg bodyweight flumequine of a 10% solution before and after experimental infection, was best described by a three-compartment open model . After intramuscular injection of the same dosage rate of a 3% flumequine suspension is was best described by the one-compartment open model with first-order absorption . The experimental infection by intratracheal administration of infectious bovine rhinotracheitis (IBR)-virus and 5 days later intrapulmonary administration of Pasteurella haemolytica produced a clear temperature rise and signs of disease expressed as Average Health Status . Subsequently, plasma Fe and Zn concentration decreased after infection . The distribution volumes Vc, Vd(area) and Vd(ss) after infection (0.07 +/- 0.04, 1.38 +/- 0.36 and 0.50 +/- 0.11 l/kg, respectively) were smaller than those before infection, but the differences were not significant (P less than or equal to 0.1) . The intravenous AUC infinity was significantly increased (21.86 +/- 3.51 to 33.85 +/- 2.97 mg.h/l, P less than or equal to 0.01) and the total body clearance (ClB) significantly decreased (0.24 +/- 0.02 to 0.15 +/- 0.01, P less than or equal to 0.01) after infection . After intramuscular injection of flumequine at 5 mg/kg as a 3% suspension, only the bioavailability, F, was significantly decreased after infection (78.5 +/- 14.3 to 59.7 +/- 21.2%, P less than or equal to 0.02) . However, this had no consequences for the dosage regimen used . The urine concentration ratio flumequine:7-hydroxy-flumequine:conjugated flumequine changed from 2:1:10 before infection to 6:1:15 after infection, which indicates that hydroxylation and glucuronidation as metabolic pathways for flumequine were decreased after Pasteurella sp . infection. Aust Vet J, 1991 Jun, 68(6), 201 - 3 Pasteurella multocida septicaemia in fallow deer (Dama dama); Carrigan MJ et al.; Thirteen of 100 fallow deer, aged between 6 months and 10 years, died over a 5 week period . The deaths occurred in 2 outbreaks 3 weeks apart . Both outbreaks were preceded by at least 3 days of cold wet and windy weather, and were associated with water-logged pastures . Affected animals were usually found dead, with a frothy blood-stained nasal discharge . In the 8 deer necropsied, gross lesions included widespread subserosal petechial haemorrhages, severe pulmonary congestion and oedema with froth-filled airways, and fibrinous pneumonia and pleurisy in 4 deer . Two deer, also, had extensive subcutaneous petechial and ecchymotic haemorrhages and oedema of skeletal musculature . Histologically, the most significant lesions were present in the lungs . Moderate to severe pulmonary congestion and oedema, with fibrinous exudation into alveoli and septal oedema, were present in all deer . In some deer these changes were accompanied by a diffuse infiltration with polymorphonuclear leucocytes . Pasteurella multocida was isolated from a range of tissues from 7 of 8 deer examined . The remaining animal had been treated with antibiotics 8 hours before death . The isolates had identical polyacrylamide gel electrophoresis patterns and were of the same antigenic type-Carter group A, Heddleston type 3,4. Zentralbl Veterinarmed B, 1991 Jun, 38(4), 265 - 8 Toxigenic Pasteurella multocida in rabbits with naturally occurring atrophic rhinitis; Frymus T et al.; In a commercial rabbitry nasal swabs were taken from 36 animals with enzootic upper respiratory disease resembling porcine atrophic rhinitis . 35 Pasteurella multocida strains were isolated from 17 rabbits . Among 30 strains tested for dermonecrotic toxin production 3, derived from 3 animals, were positive in the guinea pig skin test . 15 Bordetella bronchiseptica strains were recovered from 14 rabbits . No toxigenic strains were found among 6 isolates tested using the same method. Vet Microbiol, 1991 Jun, 28(1), 75 - 92 Relationship between the iron regulated outer membrane proteins and the outer membrane proteins of in vivo grown Pasteurella multocida; Choi-Kim K et al.; The SDS-PAGE patterns of the outer membrane protein (OMP) extracts of Pasteurella multocida strain P1059, grown under iron-restricted, iron-replete and in vivo conditions, were examined . The results showed that the iron-regulated outer membrane proteins (IROMPs) with molecular masses of 76 kDa, 84 kDa, and 94 kDa were expressed by bacteria grown in iron-restricted media . They were also expressed by in vivo grown P . multocida . Convalescent-phase sera, obtained from turkeys which had survived pasteurellosis, contained antibodies that reacted intensly with th three IROMPs . This indicated that these proteins were expressed in vivo . Bacteria expressing the IROMPs showed greater binding to Congo Red when compared to cells not expressing IROMPs . Cells expressing the IROMPs or its OMP extracts grown in iron-restricted media also showed greater binding to 59Fe-pasteurella siderophore (multocidin) when compared to bacteria or its extracts not expressing IROMPs . Convalescent-phase sera, which contained antibodies against the IROMPs, blocked this specific 59Fe-multocidin binding to IROMPs . Autoradiography was used to determine which of these IROMPs functioned as a receptor for the iron-multocidin complex . The results suggested that these three IROMPs have specific epitopes for binding to the iron multocidin complex. Vet Microbiol, 1991 Jun, 28(1), 61 - 73 Immunological properties of Actinobacillus pleuropneumoniae hemolysin I; Frey J et al.; The 105 kDa hemolysin I protein from Actinobacillus pleuropneumoniae serotype I type strain 4074 (HlyI) was shown by immunoblot analysis to be the predominant immunogenic protein if convalescent field sera or sera from pigs experimentally infected with A . pleuropneumoniae serotype 1 were used . SDS gel- and immunoblot-analysis using total culture, washed cells or culture supernatant showed that HlyI is essentially secreted and is not found attached to the bacteria . Proteins in the 105 kDa range that react strongly with anti-HlyI antibody, are produced by all serotypes and are presumed to be their hemolysins . Sera from pigs experimentally infected with each of the 12 serotypes strongly reacted with HlyI . In addition, some sera from pigs that were confirmed to be negative for A . pleuropneumoniae, also reacted with HlyI as well as with related proteins from Actinobacillus rossii and Actinobacillus suis . These two species produce proteins in the 105 kDa range which cross-react strongly with HlyI . They could be the source of the immunological reactions of the A . pleuropneumoniae-negative sera with HlyI . However, no cross-reactions could be found between HlyI and the Pasteurella haemolytica leukotoxin, the Escherichia coli alpha-hemolysin or related proteins from various hemolytic E . coli strains isolated from pigs . The immunological cross-reactions of HlyI with related proteins from A . rossii, A . suis and possibly from other bacterial species may create uncertainty in interpretation if HlyI is used as the antigen in serodiagnosis of A . pleuropneumoniae. J Clin Microbiol, 1991 Jun, 29(6), 1183 - 7 Construction of a DNA probe and detection of Actinobacillus pleuropneumoniae by using polymerase chain reaction; Sirois M et al.; A 1.5-kb Actinobacillus pleuropneumoniae 4074 DNA fragment from a genomic library was found to hybridization . No cross-hybridization hybridization . No cross-hybridization was detected with DNAs from hemolytic members of the family Pasteurellaceae . From the nucleotide sequence of the putative genomic probe, three primers were synthesized for use in polymerase chain reactions (PCRs), with 31 strains tested by using purified and crude DNA targets . PCR amplification products of 610 and 985 bp were observed in nucleic acids extracted from the 12 known serotypes and a biotype 2 strain . Template DNAs from other gram-negative and gram-positive bacteria, some of them found in the normal flora of swine and the upper respiratory tract, were not amplified by PCR . The only exception was an amplification of a similar 610- or 985-bp sequence in Actinobacillus lignieresii, a species that is closely related to A . pleuropneumoniae but that has never been isolated from swine . Amplification of specific A . pleuropneumoniae sequences by PCR directly from clinical specimens may find applications in the identification of asymptomatic carriers as well as in efforts to eradicate porcine pleuropneumonia. Zentralbl Veterinarmed B, 1991 Jun, 38(4), 306 - 14 ISCOM of BHV-1 envelope glycoproteins protected calves against both disease and infection; Merza M et al.; A subunit vaccine in the form of immunostimulating complex (iscom) was prepared to contain the envelope glycoproteins of bovine herpesvirus type 1 (BHV-1) . This iscom preparation was tested in a vaccination experiment on 4-month-old calves seronegative to BHV-1 . In this experiment, four groups with three animals per group were used . Two groups were vaccinated with the iscom preparation twice, four weeks apart, one group with 50 micrograms and the other with 100 micrograms per calf . The third group received a commercial inactivated whole-virus vaccine applying the same vaccination program . The fourth group served as control . Two weeks after the second vaccination, all the animals were challenge-infected intranasally with a virulent BHV-1 strain and four days later with a virulent Pasteurella multocida--this in order to mimic hard field conditions . When exposed to challenge infection, all the animals vaccinated with the iscom were fully protected, i.e., no virus could be recovered from their nasal secretions and no clinical symptoms were recorded . In contrast, the animals vaccinated with the commercial vaccine, responded to challenge with moderate fever and loss of appetite, and virus was isolated from the nasal secretions . The animals in the control group developed severe clinical symptoms . In the sera of iscom-vaccinated animals, the virus neutralization titers reached levels of 1/3500 or higher. Am J Pathol, 1991 May, 138(5), 1191 - 8 The role of leukocytes in the pathogenesis of fibrin deposition in bovine acute lung injury; Car BD et al.; The peculiarly fibrinous nature of bovine acute lung injury due to infection with Pasteurella haemolytica A1 suggests an imbalance between leukocyte-directed procoagulant and profibrinolytic influences in the inflamed bovine lung . Calves with experimental pneumonia produced by intratracheal inoculation with P . haemolytica A1 developed acute locally extensive cranioventral fibrinopurulent bronchopneumonia . Pulmonary alveolar macrophages (PAM) recovered by segmental lavage from affected lung lobes were 30 times more procoagulant than PAM obtained from unaffected lung lobes and 37-fold more procoagulant than PAM from control calf lungs . Unlike the enhancement of procoagulant activity, profibrinolytic activity (plasminogen activator amidolysis) of total lung leukocytes (PAM and plasminogen activator neutrophils {PMN}) was decreased 23 times in cells obtained from affected lung lobes and also was decreased four times in cells obtained from unaffected lobes of infected animals . This marked imbalance in cellular procoagulant and fibrinolytic activity probably contributes significantly to enhanced fibrin deposition and retarded fibrin removal . In addition, PAM from inflamed lungs were strongly positive for bovine tissue factor antigen as demonstrated by immunocytochemistry . Intensely tissue factor-positive PAM enmeshed in fibrinocellular exudates and positive alveolar walls were situated such that they were likely to have, in concert, initiated extrinsic activation of coagulation in the acutely inflamed lung . These data collectively suggest that enhanced PAM-directed procoagulant activity and diminished PAM- and PMN-directed profibrinolytic activity represent important modifications of local leukocyte function in bovine acute lung injury that are central to the pathogenesis of lesion development with extensive fibrin deposition and retarded fibrin removal. Vet Microbiol, 1991 May, 27(3-4), 309 - 26 Haemorrhagic septicaemia: correlation of vaccinal antibody responses in mice with protection against Pasteurella multocida strain M1404; Dawkins HJ et al.; This study examined the protection induced by oil adjuvant vaccine and broth bacterin in mice . Protective immunity was induced by both oil adjuvant and bacterin vaccination procedures . Oil adjuvant vaccination induced a 10(5)-fold increase for lethal challenge over control mice, while secondary vaccination induced a further 10-fold increase in resistance to lethal challenge . Broth bacterin induced a slightly weaker protective response with 10(4)- and 10(5)-fold increases in resistance to lethal challenge following primary and secondary vaccination, respectively . There was a significant relationship between IgG antibody levels and resistance to challenge (P = 0.026) . Protection lasted for at least 20 weeks after a primary oil adjuvant vaccination . There was also a strong and significant relationship between IgG antibody levels and the passive protection afforded by serum transfer in each experiment within this study and the overall correlation was highly significant (P = 0.00001) . There appeared to be a relationship between protection and the antibody response to major protein bands with the apparent molecular mass Mr . 94,000; 80,000; 67,000; 35,000 and 32,000 as well as to the bands in the region of the lipopolysaccharide components of P . multocida (approximately Mr, 14-15,000) . Whether protection resulted from recognition of specific antigens or was a result of both antibody levels and antibody specificity remains to be defined. Zentralbl Veterinarmed A, 1991 May, 38(4), 287 - 99 Statistical evidence for a link between bronchopneumonia and disseminated focal nephritis in pigs; Buttenschon J; An investigation on the occurrence of different pneumonia types and their possible concurrence with other pluck organ disorders was made on 6,565 pigs presented at slaughter . The frequency of disseminated focal nephritis in a bronchopneumonia group and a non-bronchopneumonia residual group, respectively, was found to differ significantly from the mean frequency of nephritis in all pig plucks examined . The number of lesioned kidneys in each of 28 samples contributing to the bronchopneumonia group and in each of 8 samples contributing to the residual group was regressed group-wise on the number of individual plucks examined in each sample; the correlation coefficient for each of these two groups was calculated . These calculations showed a highly significant link between bronchopneumonia and disseminated focal nephritis . The histopathological and bacteriological examination of some lung and kidney lesions representing the bronchopneumonia group substantiated this finding . It is concluded that the two diseases are connected through dissemination, and that Pasteurella multocida is the organism involved in the majority of cases. J Gen Microbiol, 1991 May, 137 ( Pt 5), 1067 - 71 Ultrastructural localization of the Pasteurella multocida toxin in a toxin-producing strain; iDali C et al.; Toxigenic strains of Pasteurella multocida produce the 147 kDa protein Pasteurella multocida toxin (PMT) which is responsible for the osteoclastic bone resorption in progressive atrophic rhinitis in pigs and induces such resorption in all experimental animals tested so far . In the present study we have carried out immunocytochemistry on formaldehyde- and glutaraldehyde-fixed ultracryocut P . multocida using a pool of monoclonal antibodies against different epitopes on PMT as the first layer and affinity purified rabbit anti-mouse IgG as the second layer . Goat anti-rabbit IgG conjugated with 5 nm gold particles was used as marker . The gold particles were silver-enhanced prior to examination in the transmission electron microscope . Whole bacteria were also immunostained after fixation and critical point drying and examined by scanning transmission electron microscopy . The results showed that PMT was located in the cytoplasm of P . multocida . PMT could not be detected on intact, undamaged P . multocida by scanning electron microscopy . Neither pili nor flagella could be detected on the surface of the negatively stained P . multocida strains investigated . PMT has a series of characteristics encompassed in the definition of an exotoxin . However, that PMT was not secreted by living intact P . multocida is unexpected for an exotoxin. Microb Pathog, 1991 May, 10(5), 411 - 7 Neutralizing monoclonal antibodies to Pasteurella haemolytica leukotoxin affinity-purify the toxin from crude culture supernatants; Gentry MJ et al.; The leukotoxin of Pasteurella haemolytica is a major virulence factor of the organism . It is an unstable protein which has proven very difficult to purify using traditional techniques . Hybridomas secreting monoclonal antibodies (mAbs) to P . haemolytica leukotoxin were derived from spleen cells of a mouse immunized with crude culture supernatant . Five hybridomas secreting mAbs specific for the leukotoxin were stabilized . Each of the mAbs reacted with a protein of approximately 100 kDa in toxic culture supernatants, and two of them completely neutralized the toxin in vitro . Affinity chromatography of crude culture supernatant on a column prepared with one of the neutralizing mAbs resulted in the isolation of biologically active toxin. Res Vet Sci, 1991 May, 50(3), 368 - 70 Evidence of phenotypic dichotomy within an individual Pasteurella multocida type strain and among some haemorrhagic septicaemia-causing field isolates; Dawkins HJ et al.; Haemorrhagic septicaemia-causing strains of Pasteurella multocida were identified by a disease-specific ELISA . Some strains, however, were of the same serotype as those which cause haemorrhagic septicaemia (HS) but were negative when tested in the disease specific ELISA . The suspect false negative isolates were passaged in mice and retested in the HS ELISA with the same result . Immunoelectron microscopy was used to examine further these suspect HS-causing strains . Monoclonal antibodies and protein A-gold showed that the suspect negative organisms were a mixture of phenotypes with less than 10 per cent, and usually less than 2 per cent, of the population expressing HS-associated epitopes . The degree of staining on the organisms expressing the HS-epitopes was of the same intensity as the positive control organism . Expression of the HS-associated epitopes is presumably too low to allow detection in the current HS ELISA. J Wildl Dis, 1991 Apr, 27(2), 296 - 316 Chronic upper respiratory tract disease of free-ranging desert tortoises (Xerobates agassizii); Jacobson ER et al.; Seventeen desert tortoises, Xerobates agassizii, with upper respiratory tract disease were examined; thirteen were euthanatized for necropsy . Four normal control desert tortoises from a clinically healthy population were similarly evaluated . Hemoglobin and phosphorus values were significantly (P less than or equal to 0.05) lower and serum sodium, urea, SGOT, and cholesterol values were significantly higher in ill tortoises compared to controls . No significant differences in concentrations of serum or liver vitamins A and E were found between the two groups . While no significant differences were found for concentrations of lead, copper, cadmium, and selenium, the livers of ill tortoises had higher concentrations of mercury and iron . Lesions were found consistently in the upper respiratory tract (URT) of ill tortoises . In all ill tortoises dense infiltrates of lymphocytes and histiocytes obscured the mucosal epithelium and underlying glands . The mucosal epithelium was variably dysplastic, hyperplastic, and occasionally ulcerated . Electron microscopic studies revealed small (350 to 900 nm), pleomorphic organisms resembling Mycoplasma sp., in close association with the surface epithelium of the URT of ill tortoises . Pasteurella testudinis was cultured from the nasal cavity of all ill tortoises and one of four control tortoises . A Mycoplasma sp . was cultured from the nasal passageways of four ill tortoises and was ultrastructurally similar to the pleomorphic organism present on the mucosa in tissue section. Vet Microbiol, 1991 Apr, 27(2), 169 - 74 Immunity induced in rats vaccinated with toxoid prepared from heat-labile toxin produced by Pasteurella multocida serogroup D; Thurston JR et al.; Rats were vaccinated with a toxoid (D-toxoid) prepared from purified heat-labile toxin (D-toxin) produced by Pasteurella multocida serogroup D . Vaccination of rats with D-toxoid prevented death and other effects of D-toxin (hepatic necrosis, development of elevated leukocyte counts, lymphopenia, neutrophilia, and elevated complement titers) that occurred in phosphate buffered saline (PBS)-vaccinated control rats. J Comp Pathol, 1991 Apr, 104(3), 233 - 43 Experimental pneumonia in mice produced by combined administration of Bordetella parapertussis and Pasteurella haemolytica isolated from sheep; Jian Z et al.; One-hundred-and-thirty-seven, 3-week-old, Swiss mice were inoculated intranasally with Bordetella parapertussis and Pasteurella haemolytica which had been isolated from naturally occurring cases of chronic non-progressive pneumonia in sheep . The combined administration produced a significantly more severe bronchopneumonia which occurred earlier, persisted for a longer period and involved a higher percentage of mice than that which was produced with B . parapertussis or P . haemolytica alone . These findings demonstrate an additive or synergic action between the two agents or their metabolic products, and provide indirect evidence that such interaction may occur in ovine chronic non-progressive pneumonia. Infect Immun, 1991 Apr, 59(4), 1470 - 5 Antibodies to outer membrane proteins but not to lipopolysaccharide inhibit pulmonary proliferation of Pasteurella multocida in mice; Lu YS et al.; The role of rabbit antibodies against Pasteurella multocida outer membrane proteins and lipopolysaccharides (LPS) in resistance remains unknown . Pooled immune sera against P . multocida outer membranes were prepared from specific-pathogen-free rabbits immunized with sucrose gradient-purified P . multocida outer membranes . Western immunoblotting showed that purified outer membrane protein antibodies reacted strongly against the outer membrane proteins but not the purified LPS . Affinity-purified LPS antibodies exhibited strong reactivity against purified LPS and very little reactivity against outer membrane vesicles . Mice were inoculated intranasally with immune serum or normal rabbit serum, challenged intranasally with 10(6) CFU of P . multocida, and euthanatized 48 h later to determine the number of P . multocida organisms in the lungs . Mice inoculated with pooled immune serum had a 3,300-fold reduction (P less than 0.001) in the numbers of P . multocida in the lungs as compared with the controls . Similarly, mice inoculated with purified outer membrane protein antibodies had a 201-fold reduction (P less than 0.001) in the numbers of P . multocida . Conversely, mice inoculated with affinity-purified LPS antibodies had a 1.1-fold reduction (P greater than 0.50) in the numbers of P . multocida . These results show that antibodies against the outer membrane proteins but not the LPS are the components of rabbit immune sera which inhibit P . multocida proliferation in mouse lungs. J Vet Diagn Invest, 1991 Apr, 3(2), 124 - 6 In vitro antimicrobial susceptibility of Pasteurella haemolytica and Pasteurella multocida recovered from cattle with bovine respiratory disease complex; Post KW et al.; The antimicrobial susceptibilities of 421 Pasteurella haemolytica and 158 P . multocida isolates recovered from cattle with respiratory disease were determined with a microdilution minimal inhibitory concentration test system . Isolates were analyzed for patterns of resistance to ampicillin, ceftiofur, erythromycin, gentamicin, penicillin, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, tetracycline, and tylosin . All isolates tested were found susceptible to ceftiofur and sulfachlorpyridazine . Pasteurella haemolytica isolates were resistant to ampicillin, penicillin, sulfadimethoxine, tetracycline, and tylosin . Pasteurella multocida isolates were resistant to sulfadimethoxine, tetracycline, and tylosin. Vet Immunol Immunopathol, 1991 Apr, 28(2), 157 - 63 Pasteurella haemolytica A1 purified capsular polysaccharide does not stimulate interleukin-1 and tumor necrosis factor release by bovine monocytes and alveolar macrophages; Czuprynski CJ et al.; Purified capsular polysaccharide (CPS) stimulated significant release of interleukin-1 (IL-1) activity from bovine blood monocytes but not alveolar macrophages in vitro . The ability of CPS to induce IL-1 release was resistant to boiling and inhibited by the addition of polymyxin beta . Thus, it is likely that the IL-1 release stimulated by CPS resulted from the small amount of contaminating lipopolysaccharide (LPS) that was present (an estimated 5 pg LPS per microgram CPS) rather than to a direct effect of CPS . Tumor necrosis factor activity was not detected in the culture supernatants of bovine monocytes incubated with purified CPS for 1-18 h in vitro. Avian Dis, 1991 Apr-Jun, 35(2), 392 - 6 In vivo antigen expression by Pasteurella multocida; Glisson JR et al.; Pasteurella multocida was purified from the blood of turkeys affected with acute fowl cholera, and membrane preparations from those bacteria were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized on immunoblots . Antigens were detected in the membranes of these in vivo-propagated bacteria that were not detected in membrane preparations of the same P . multocida strain grown in vitro . The unique antigens were detected in the detergent-insoluble phase and were enriched to various degrees by different detergents. Avian Dis, 1991 Apr-Jun, 35(2), 251 - 6 Comparison of live avirulent M-9, Minnesota, and CU fowl cholera vaccines; Friedlander RC et al.; The M-9 and Minnesota (MN) avirulent Pasteurella multocida vaccines were evaluated and compared with the Clemson University (CU) vaccine, which had been shown to be highly effective in preventing fowl cholera in turkeys . Neither the M-9 nor the MN vaccine given in the drinking water was as effective as the CU vaccine in protecting turkeys against challenge with virulent P . multocida . When grown in brain-heart infusion (BHI) agar as recommended, the M-9 was not as efficacious as when it was grown in BHI broth . The M-9 was as effective as the CU vaccine only when grown in BHI broth and given at 10 times the standard dosage . Injection of the M-9 vaccine into the air spaces of the head at a site near the caudal rim of the ear after one vaccination in the drinking water was not as effective for hyperimmunizing potential breeders as was the CU vaccine injected at the same site . A microtiter agglutination test demonstrated a significant (P less than 0.05) correlation between the level of anti-P . multocida antibody found 1 week after vaccination and survival after challenge with virulent P . multocida. Can J Vet Res, 1991 Apr, 55(2), 128 - 38 Vaccination against progressive atrophic rhinitis with a recombinant Pasteurella multocida toxin derivative; Nielsen JP et al.; Vaccination against progressive atrophic rhinitis using a purified recombinant derivative of the Pasteurella multocida toxin (PMT), was carried out . Ten pregnant gilts were vaccinated twice with the nontoxic derivative (dO) which apart from a lack of 121 amino acids had an amino acid sequence identical to PMT, while seven gilts were vaccinated with a purified, formaldehyde treated, native PMT and ten gilts served as non-vaccinated controls . The resulting piglets were inoculated intranasally with Bordetella bronchiseptica and toxigenic P . multocida . Among piglets from the nonvaccinated gilts all except one developed clinical atrophic rhinitis and 90% developed severe turbinate atrophy while only a few pigs in the vaccinated groups developed clinical or pathological signs of disease . Gilt colostra from the two vaccinated groups had similar mean anti-PMT titers and the mean titers in the offspring's sera from these groups were nearly identical throughout the study . No pigs born from unvaccinated gilts were seropositive until 8 wk of age (7 wk post-challenge) but 23% became seropositive at slaughter . The infection rate with toxigenic P . multocida in piglets and the total number of P . multocida colonies cultured from nasal swabs were significantly reduced at 5 wk and 8 wk of age in the vaccinated groups, when compared to controls . There was a significantly improved weight gain (greater than 9%) from birth to slaughter in offspring from vaccinated gilts . No significant differences in feed conversion rate or % lean meat were observed among the groups . The study showed the excellent immunoprotective properties of the nontoxic derivative of the PMT molecule. Vet Microbiol, 1991 Apr, 27(2), 175 - 85 Proteins and antigens of Pasteurella multocida serotype 1 from fowl cholera; Ireland L et al.; The protein profiles of Pasteurella multocida serotype 1 isolates and the response of chickens to serotype 1 antigens were investigated using SDS-PAGE . Patterns obtained with Coomassie blue staining of soluble protein extracts were similar . The major difference between isolates was the position of one of the major proteins in the 34-38 kDa region . When chickens were experimentally infected with a clinical isolate of P . multocida serotype 1 various proteins were recognised by immunoblotting, including one with a relative molecular weight of 34 kDa; however, no reactions were observed in the region where LPS is known to migrate . When these infection sera were used in an EIA with purified LPS obtained from Heddleston serotype 1 type strain (X-73) they reacted strongly . Serum used for serotyping isolates in the gel diffusion precipitin test recognised many antigens in common with sera from infected birds, but some antigens were specific to typing sera. Lab Anim Sci, 1991 Apr, 41(2), 162 - 5 An enzyme-linked immunosorbent assay for detection of chronic subclinical Pasteurella pneumotropica infection in mice; Manning PJ et al.; Serum samples from seventy-five, 3- to 12-week-old and 16 retired breeder male Swiss mice from a conventional colony with enzootic chronic subclinical Pasteurella pneumotropica infection were tested by enzyme-linked immunosorbent assay (ELISA) and Western blots for IgG antibodies to whole cell (WC) and lipooligosaccharide (LOS) antigens of P . pneumotropica . In 3- to 12-week-old mice, serum antibody levels to LOS exceeded those to the WC preparation . Western blots of sera from mice in this age group substantiated that a major component of the early IgG antibody response was directed against LOS antigens . Higher antibody levels to both antigen preparations in 3-week-old mice compared to mice 4 and 6 weeks old were interpreted as reflecting a decline in antibodies acquired from the dam . Active immunity indicative of infection was first detected at 8 weeks of age . Serum samples from retired breeder mice (28 weeks of age) also had substantial antibody titers to LOS but, in contrast to sera from mice in the younger age groups, retired breeders had significantly greater IgG reactivity to WC preparations than to LOS antigens . The superior specificity of the LOS antigen compared to the WC preparation in the ELISA was demonstrated by testing serum samples from retired breeder mice against WC and LOS antigens from P . ureae, P . multocida, and P . hemolytica . The reactivity of IgG against LOS antigens from these organisms was negligible, whereas substantial titers were evident to WC antigens . This ELISA, using LOS preparations as antigen, is a useful serologic assay for the detection of subclinical P . pneumotropica infection in mice. Vet Microbiol, 1991 Apr, 27(2), 159 - 68 Lymphocyte subpopulations in peripheral blood of lambs experimentally infected with Pasteurella haemolytica; Sharma R et al.; The lymphocyte subpopulations in peripheral blood obtained from eleven lambs experimentally infected with Pasteurella haemolytica were compared with those obtained from eight control lambs by flow cytometry, using a panel of monoclonal antibodies against specific lymphocyte epitopes . Experimental infection with P . haemolytica was characterized by a transient but significant reduction in SBU-T1+ (CD5+) T cells and SBU-T4+ (CD4+ or helper) T lymphocytes (P less than 0.05) and a significant rise in lymphocytes which did not express the LCA p220 epitope and the pan T cell surface marker (CD5-LCA p220-) ("null") . The reductions in CD5+ and CD4+ lymphocytes occurred 24 h after experimental infection, returning to preinoculation levels 5 days post inoculation (DPI) . Five to 9 days after experimental infection, there was a significant increase in the number of lymphocytes, which expresses the pan T cell surface marker (CD5+) but which were CD4-CD8- . Lymphocyte transformation responses to the mitogen phytohaemagglutinin (PHA) were significantly reduced 24 h after experimental infection with P . haemolytica (P less than 0.05). Infect Immun, 1991 Apr, 59(4), 1387 - 93 Recombinant derivatives of Pasteurella multocida toxin: candidates for a vaccine against progressive atrophic rhinitis; Petersen SK et al.; Potential vaccine components for protection against atrophic rhinitis in pigs were developed . This was achieved by deletion mutagenesis of the gene encoding the Pasteurella multocida toxin . Four purified toxin derivatives lacking different and widely separated regions in the amino acid sequence were characterized by a lack of toxic activity . One such component was shown to induce efficient protection of vaccinated female mice and their offspring against challenge with purified P . multocida toxin. Lab Anim Sci, 1991 Apr, 41(2), 151 - 6 Heat-labile toxin-producing isolates of Pasteurella multocida from rabbits; Suckow MA et al.; Five of one hundred forty seven isolates of Pasteurella multocida from rabbits were found to produce heat-labile toxin . Each isolate was assayed for the ability of potassium thiocyanate (KSCN) extracts to cause dermonecrosis in guinea pig skin, ability of bacteria or filtrates to cause cytotoxicity in cell cultures, and reactivity with monoclonal antibodies to heat-labile P . multocida toxin . Five capsular type D isolates produced dermonecrosis and reacted with monoclonal antibodies to toxin . Filtrates of all five of these isolates were cytotoxic for cell cultures . Potassium thiocyanate extracts of all five isolates caused pleuritis and pneumonia in rabbits after intranasal inoculation . Turbinate atrophy was seen in 5 of 19 rabbits inoculated intranasally with toxic extracts . Heat-labile toxin was not produced by 109 capsular type A isolates or 19 nontypable isolates. J Am Vet Med Assoc, 1991 Mar 15, 198(6), 1052 - 6 Development of pneumonia in desert bighorn sheep after exposure to a flock of exotic wild and domestic sheep; Callan RJ et al.; From 1986 to 1989, 5 desert bighorn sheep (3 Ovis canadensis mexicana and 2 O c nelsoni), ranging in age from 2 to 3 years, were exposed to a flock of exotic wild and domestic sheep to potentially achieve naturally acquired pneumonia . Pasteurella multocida was isolated from nasal samples from 4 of 6 sheep randomly sampled from the flock . Bighorn sheep were exposed individually and each exposure period was a trial . Treatment before and after exposure varied and included combinations of alpha interferon, antibiotics, anti-inflammatory drugs, and vaccines . Treatments were chosen on the basis of recommendations of others for treating pneumonia in desert bighorn sheep as well as our own experience in sheep and cattle . Regardless of treatment used, bighorn sheep in trials 1 to 4 developed signs of pneumonia within 10 to 14 days of exposure . Bighorn sheep in trials 1 to 3 died within 11 to 17 days of initial exposure . In trial 4, the bighorn sheep was isolated from the carrier sheep for treatment of pneumonia on day 14 and died on day 30 . Pasteurella multocida was isolated from lung tissue in 3 of the 4 bighorn sheep . On the basis of results of trials 1 to 4, a more in depth clinical study was conducted in trial 5 . Nasal and blood specimens were collected prior to and during trial 5 for bacteriologic culturing and serologic testing for bovine viral diarrhea virus, infectious bovine rhinotracheitis, parainfluenza-3 virus, and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS) J Biol Chem, 1991 Mar 15, 266(8), 4840 - 7 Pasteurella multocida toxin, a potent mitogen, increases inositol 1,4,5-trisphosphate and mobilizes Ca2+ in Swiss 3T3 cells; Staddon JM et al.; Pasteurella multocida toxin, both native and recombinant, is an extremely potent mitogen for Swiss 3T3 cells and acts to enhance the formation of total inositol phosphates (Rozengurt, E., Higgins, T., Changer, N., Lax, A.J., and Staddon, J.M . (1990) Proc . Natl . Acad . Sci . U.S.A . 87, 123-127) . P . multocida toxin also stimulates diacylglycerol production and activates protein kinase C (Staddon, J.M., Chanter, N., Lax, A.J., Higgins, T.E., and Rozengurt, E . (1990) J . Biol . Chem . 265, 11841-11848) . Here we analyze, by {3H}inositol labeling and high performance liquid chromatography, the inositol phosphates in recombinant P . multocida toxin-treated cells . Recombinant P . multocida toxin stimulated increases in {3H}inositol 1,4,5-trisphosphate ({3H}Ins(1,4,5)P3) and its metabolic products, including Ins(1,3,4,5)P4, Ins(1,3,4)P3, Ins(1,4)P2, Ins(4/5)P, and Ins(1/3)P . The profile of the increase in the cellular content of these distinct inositol phosphates was very similar to that elicited by bombesin . Furthermore, recombinant P . multocida toxin, like bombesin, mobilizes an intracellular pool of Ca2+ . Recombinant P . multocida toxin pretreatment greatly reduces the Ca2(+)-mobilizing action of bombesin, consistent with Ca2+ mobilization from a common pool by the two agents . The enhancement of inositol phosphates and mobilization of Ca2+ by recombinant P . multocida toxin were blocked by the lysosomotrophic agents methylamine, ammonium chloride, and chloroquine and occurred after a dose-dependent lag period . The stimulation of inositol phosphate production by recombinant P . multocida toxin persisted after removal of extracellular toxin, in contrast to the reversibility of the action of bombesin . Recombinant P . multocida toxin, unlike bombesin and guanosine 5'-O-(gamma-thiotriphosphate), did not cause the release of inositol phosphates in permeabilized cells . These data demonstrate that recombinant P . multocida toxin, acting intracellularly, stimulates the phospholipase C-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate. Vet Microbiol, 1991 Mar, 27(1), 63 - 78 Cloning and expression of a 30 kDa surface antigen of Pasteurella haemolytica; Craven RC et al.; Pasteurella haemolytica biotype A serotype 1 is the principal etiologic agent of bovine pneumonic pasteurellosis . A clear understanding of the pathogenesis of this disease and the mechanisms of resistance to it has been limited by a lack of information on the important antigens of the organisms . Using recombinant DNA techniques we have cloned a segment of DNA from P . haemolytica A1 that encodes three proteins of 28, 30, and 32 kDa . Two of these proteins, 30 and 28 kDa, react strongly on a Western blot with a bovine serum raised against live cells of P . haemolytica A1 . The gene for the 30 kDa protein was localized to a 3.1 kbp EcoRI fragment, and expression of the 30 kDa protein was found to be independent of an E . coli promoter . The 30 kDa protein comigrated with a 30 kDa P . haemolytica protein that was susceptible to radioiodination and presumably exposed on the bacterial cell surface . The other principal radiolabeled P . haemolytica proteins were 100, 45, and 15 kDa . Antibodies against the 30 kDa protein, isolated from E . coli carrying the recombinant plasmid, recognized 30 kDa and 15 kDa proteins in P . haemolytica serotypes 1-15 and caused agglutination of whole P . haemolytica A1 cells . Cattle vaccinated with live P . haemolytica, P . haemolytica outer membrane proteins, or the cloned 30 kDa protein developed antibodies to the cloned 30 kDa protein as detected by Western blotting and densitometry . Sera were obtained from cattle vaccinated with live or killed P . haemolytica or saline and challenged with P . haemolytica . Those sera were evaluated for antibody responses to the cloned 30 kDa protein . High antibody responses to the 30 kDa protein significantly correlated (P less than 0.01) with resistance to challenge . From these studies it is concluded that the 30 kDa protein represents a surface antigen of P . haemolytica A1 that may be important in inducing immunity to P . haemolytica. Am J Vet Res, 1991 Mar, 52(3), 453 - 7 Lysis of bovine platelets by Pasteurella haemolytica leukotoxin; Clinkenbeard KD et al.; Pasteurella haemolytica A1 culture supernatants caused rapid cytolysis (less than 5 minutes) of isolated bovine platelets as measured by leakage of the cytoplasmic enzyme lactate dehydrogenase (LD) . The platelet lytic factor had several features similar to P haemolytica leukotoxin . Like P haemolytica leukotoxin, the platelet lytic factor was produced by P haemolytica during logarithmic growth phase, was heat-labile, and was active against target cells (platelets) from ruminant species (cattle and sheep), but not from non-ruminant species (horses, pigs, and human beings) . Additionally, the platelet lytic factor was neutralized with antileukotoxin rabbit serum . The amount of LD leaked by a fixed concentration of bovine platelets was proportional to the amount of toxin added at low toxic doses and became maximal at 88 +/- 11% of the total platelet LD activity for high doses of toxin . When a fixed dose of toxin was used and the platelet concentration was varied, LD leakage was initially proportional to the platelet concentration, but plateaued at higher platelet concentrations . The platelet lytic factor required Ca2+ and was inhibited by addition of the Ca2+ chelator ethylene glycol-bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid . Toxin-mediated platelet damage may be important in thrombi formation and fibrin exudation typically associated with P haemolytica pleuropneumonia of cattle. APMIS, 1991 Mar, 99(3), 291 - 4 Isolation of Pasteurella caballi from an infected wound on a veterinary surgeon; Bisgaard M et al.; Comparison of phenotypical characters obtained from the type strain of Pasteurella caballi and a previously unclassified P.sp., isolated from an infected wound on a veterinary surgeon, allowed classification of the P.sp . with P . caballi . The P.sp . was isolated in a mixed culture with Escherichia coli and probably represents the first human isolate of P . caballi. Vet Microbiol, 1991 Feb 15, 26(4), 349 - 58 Interaction of bovine alveolar macrophages with Pasteurella haemolytica A1 in vitro: modulation by purified capsular polysaccharide; Czuprynski CJ et al.; Preincubation of bovine alveolar macrophages with Pasteurella haemolytica A1 purified capsular polysaccharide markedly reduced the phagocytosis of P . haemolytica A1 in vitro in a dose-dependent manner . Both the percentage of macrophages with intracellular P . haemolytica and the mean number of bacteria per ingesting macrophage were decreased by treatment with capsular polysaccharide . Untreated bovine alveolar macrophages had little ability to kill P . haemolytica A1 in vitro at bacteria to macrophages ratios of 1 to 1 or greater; at lower ratios of bacteria to macrophages (1 to 3 or less) modest killing was observed . Preincubation with capsular polysaccharide impaired phagocytosis and killing of P . haemolytica A1 by alveolar macrophages even when the macrophages outnumbered the bacteria . These data indicate that P . haemolytica capsul