Haemolytica Vaccine Research Articles

Onset of serum antibodies to Pasteurella (Mannheimia) haemolytica following vaccination with five commercial vaccines

The purpose of this study was to compare the antibody responses of cattle vaccinated with one of five commercial non-living P. haemolytica vaccines during the first two weeks after a single vaccination. Antibodies to surface antigens (whole cells) and to the leukotoxin (LKT) were quantified at Days 7 and 14 after vaccination. In addition, antibodies to specific P. haemolytica whole cell protein antigens were determined by immunoblots using sera from vaccinated and control calves. Three hundred pre-weaned, mixed beef breed steers and heifers, greater than three months old, were equally divided among five vaccinated and one placebo groups. Cattle were subcutaneously injected with one of the following commercial P. haemolytica vaccines: One Shot, One Shot Ultra 8, Pyramid 4+Presponse SQ, Pulmo-guard PH-M or Poly-Bac B 1. Antibody responses to both LKT and whole cells were highest on Day 7 for One Shot and One Shot Ultra. By Day 14, Pulmo-Guard stimulated serum antibodies to both antigen preparations that were equivalent to those for One Shot and One Shot Ultra. Serum antibodies to LKT and whole cells were detected in the Pyramid/Presponse- and Poly-Bac 1 - vaccinated groups; however, those responses were not significantly different from the placebo group. Each vaccine, except for the Pyramid 4/Presponse - vaccinated group, stimulated antibodies to similar P. haemolytica somatic proteins, particularly at 200, 100, 60-70, 45, 35 and 25 kDa. Sera from the Pyramid 4/Presponse-vaccinated group recognized fewer protein bands, mainly those at 200, 70-75, 48 and 35 kDa. In conclusion, various commercial vaccines induced differences in the rapidity and the intensity of serum antibody responses to P. haemolytica whole cells and LKT.

Effects of vaccinating beef dams precalving and calves preweaning with a Pasteurella haemolytica vaccine (2001)

Our objective was to determine if vaccinating dams precalving and calves preweaning for Pasteurella haemolytica could effect serum antibody titers in dams, and the pre- and post-weaning health and performance of their calves. Vaccination increased serum antibody titers in multiparous cows, but not first-calf heifers. Precalving vaccination had minimal effects on mortality and morbidity of calves before or after weaning. Subsequent steer feedlot gains were unaffected by precalving and preweaning vaccinations and carcasses were not affected. However, heifers' weight gains were greater from weaning to one year of age when reared by vaccinated dams.

Immunologic responses of domestic and bighorn sheep to a multivalent Pasteurella haemolytica vaccine.

The efficacy of a Pasteurella haemolytica vaccine (serotypes A1, A2, and T10) to induce humoral antibodies and alter colonization of the upper respiratory tract by related P. haemolytica spp. strains was evaluated in 10 bighorn (Ovis canadensis canadensis) and 10 domestic (Ovis aries) sheep. Sheep of each species were divided into five pairs based on age and history of respiratory disease. One sheep in each pair was vaccinated twice 2 wk apart with 2 ml of vaccine (VAC group) and the remaining animals (NV group) were injected with 2 ml of sterile saline. Mild, transient lameness was the only observed adverse effect. Blood sera from the sheep were tested for agglutinating antibodies against whole cells of A1, A2, and T10 and for leukotoxin neutralizing antibodies. Antibody titers were expressed as the reciprocal log2 of the highest reactive dilutions. Domestic sheep > 1-yr-old and two bighorn sheep with a history of A1 infection had higher titers throughout the study against A1 cells than domestic sheep < 1-yr-old and bighorns without a history of A1 infection. Both domestic and bighorn sheep had log2 titers of 8 to 12 against A2 cells and 6 to 12 against T10 cells during this time. Bighorn sheep in the VAC group had 2 to 32 fold titer increases for A1 cells by 2 wk post-vaccination (PV) compared to 0 to 2 fold increases in VAC domestic sheep. Two to 16 and 0 to 8 fold increases in antibodies titers to A2 and T10 cells, respectively, were detected in sera of both VAC groups. Sera of bighorn sheep with a history of respiratory disease and all domestic sheep had log2 leukotoxin neutralizing antibody titers of 4 to 14 in contrast to < or = 2 in sera of bighorn sheep without a history of respiratory disease. Neutralizing antibody titers of two bighorns without a history of respiratory disease in the VAC group increased from log2 0 to 5 in one and from 0 to 9 in the other 2 wk PV. Antibody increases in these animals were no longer evident at 16 wk PV while titers of animals with histories of disease remained relatively stable. The types and numbers of Pasteurella spp. isolated from nasal and pharyngeal swabs varied throughout the study without conclusive evidence of suppression of colonization. Although the animals were not experimentally challenged to determine the efficacy of the vaccine, one VAC and one NV bighorn sheep died following introduction of an A2 P. haemolytica strain when leukotoxin neutralizing antibodies had returned to pre-vaccination levels. This vaccine appeared to be safe for use in bighorn sheep and stimulated moderate but transient increases in antibody levels which should provide some protection against naturally occurring disease. A vaccine which would induce production of high and maintained antibodies against multiple strains of P. haemolytica would be valuable for use in bighorn sheep maintained in captivity or when captured for relocation.

Duration of serum antibody responses following vaccination and revaccination of cattle with non-living commercial Pasteurella haemolytica vaccines

This study was designed to determine the duration of serum antibody responses to Pasteurella haemolytica whole cells (WC) and leukotoxin (LKT) in weanling beef cattle vaccinated with various non-living P. haemolytica vaccines. Serum antibodies to P. haemolytica antigens were determined periodically through day 140 by enzymelinked immunosorbent assays. At day 140, cattle were revaccinated, and antibody responses periodically determined through day 196. Three vaccines were used in two experiments (A and B), OneShot™, Presponse ® HP tK , and Septimune ® PH-K. In general, all three vaccines between 7 and 14 days induced antibody responses to WC after vaccination. Antibodies to LKT were induced with OneShot and Presponse. Revaccination at days 28 and 140 usually stimulated anamnestic responses. Serum antibodies to the various antigens remained significantly increased for up to 84 days after vaccination or revaccination. The intensity and duration of antibody responses were variable depending on the experiment and vaccines used. Vaccination with OneShot usually stimulated the greatest responses to WC. Vaccination with OneShot or Presponse resulted in equivalent primary anti-LKT responses. In experiment B, spontaneous seroconversion was found in numerous calves on day 112. Revaccination of those cattle at day 140 resulted in markedly variable antibody responses such that several groups had no increase in antibody responses.

Proliferative responses of peripheral blood leucocytes of sheep infected with Trypanosoma evansi.

The effects of Trypanosoma evansi on the proliferative responses of ovine peripheral blood leucocytes (PBL) were examined in in vitro cell culture systems. Sheep were vaccinated against pneumonic pasteurellosis with a monovalent Pasteurella haemolytica vaccine and then infected with T. evansi TREU 2143. From 1 week post-infection (p.i.), the PBL were separated and stimulated in cultures with either Concanavalin A (Con A), bacterial lipopolysaccharide (LPS), pasteurella antigen (P.ag), or homologous trypanosome antigen (T.ag). The proliferative responses of the cells to Con A and LPS were significantly (P < 0.001) suppressed by the infection. This suppression was associated with active infection, as treatment of the sheep with a trypanocide restored the proliferative ability of the cells to both mitogens. Similarly, active infection significantly (P < 0.001) suppressed specific responses to P.ag and T.ag but although treatment resulted in full specific proliferative responsiveness to the homologous trypanosome antigen, the same was not true of P.ag, in which the responsiveness of cells from uninfected vaccinated sheep to it were still significantly higher (P < 0.001) than those of cells from infected sheep.

Increase in CD5 + B cells and depression of immune responses in sheep infected with Trypanosoma evansi

The effects of Trypanosoma evansi on the cellular and humoral immune responses of sheep to Pasteurella haemolytica vaccine were studied. Peripheral blood lymphocytes (PBLs) from the sheep were analysed using single and double-colour indirect immunofluorescence staining and flow cytometry to monitor changes in circulating B and T cell subsets. Serum antibody responses were assayed using the enzyme-linked immunosorbent assay technique (ELISA), in addition to measuring local skin reactions at the site of vaccine administration. Results showed significant increases in circulating B cells in all sheep after the primary ( p<0.01) and secondary ( p<0.001) vaccinations although the increases were much more dramatic in the T. evansi-infected sheep. In addition, infection induced significant increases ( p<0.004) both in proportions and numbers of CD5 + B cells with more than 70% of circulating B cells expressing the CD5 antigen and showed significant differences ( p<0.01) from those of control sheep in which vaccination alone failed to induce similar increases. Also, infection resulted in significant decreases in CD5 + ( p<0.003), CD4 + ( p<0.03) and CD8 + ( p<0.03) T cell subsets in contrast to their increases in all control animals after vaccination. Moreover, there were significant suppression of both local skin reaction ( p<0.005) and serum Ig and IgG 1 ( p<0.001) antibody responses to the vaccine antigen.

Induction of CD4+CD8+ double positive T cells and increase in CD5+ B cells in efferent lymph in sheep infected with Trypanosoma evansi.

The effects of Trypanosoma evansi on efferent lymphocyte phenotypes draining from a lymph node primed with Pasteurella haemolytica vaccine were studied in sheep. The prefemoral efferent lymphatic ducts of the infected sheep along with those of two uninfected sheep were surgically cannulated. Lymph was collected and lymphocytes recovered from it analysed by two-colour indirect immunofluorescence staining and cytofluoremetry in a fluorescence activated cell analyser (FACSCAN). The study showed the appearance and persistence of T. evansi in the efferent lymph for a long period of time and the appearance of CD4+CD8+ (double positive, DP) T lymphocytes in the efferent lymph of infected animals. The infection also resulted in increases in CD5+ B cells in the prefemoral efferent lymph. In addition, there were decreases in the output of conventional B cells, CD5+ and CD4+ T cell subsets but large increases in CD8+ cells followed by terminal depletion of all cell subsets. In contrast, inoculation of sheep with pasteurella vaccine antigen alone produced little alterations in the proportions, but large increases in the numbers of all T cell subsets except that of CD8+ cells which also showed little variation; and there was a concurrent increase in the numbers and proportions of efferent B cells. In addition, the abnormal expression of DP and CD5+ B cells did not occur in the uninfected vaccinated sheep. It is concluded that these abnormal changes in the kinetics of efferent lymphocyte phenotypes are likely to play a role in the genesis of the generalized immunosuppression seen in trypanosome-infected hosts.

Evaluation of a multivalent Pasteurella haemolytica vaccine in bighorn sheep: safety and serologic responses.

We examined effects of a multivalent Pasteurella haemolytica vaccine (serotypes A1, A2, T10) on humoral immune responses and P. haemolytica isolation rates in bighorn sheep (Ovis canadensis). Thirty captive bighorns, divided into groups of three on the basis of age, sex, and previous history of pneumonic pasteurellosis, received 0, 1, or 2 vaccine doses. Mild, transient lameness in most bighorns 1 day after initial vaccination was the only adverse effect observed. Oropharyngeal (> or = 75%) and nasal (< or = 50%) isolation rates for P. haemolytica did not differ among treatment groups. Ten of 36 distinguishable biogroup variants accounted for about 87% of the 464 P. haemolytica isolates from bighorns, but prevalences of specific biogroups were not affected by vaccination. Bighorns receiving 1 or 2 vaccine doses showed marked elevations in leukotoxin neutralizing antibody titers beginning 1 wk after vaccination. Agglutinating antibody titers to serotype A1 and A2 surface antigens were also elevated in vaccinated bighorns within 2 wk after vaccination; agglutinating antibody titers to serotype T10 surface antigens were relatively high in all three groups but appeared unaffected by vaccination. Vaccination 7 to 14 wk prior to parturition elevated leukotoxin neutralizing antibody titers in colostrum, but neither leukotoxin neutralizing nor serotype A1 surface antigen agglutinating antibody titers differed through 16 wk of age among lambs born to dams from different vaccine dose groups. Our data demonstrate that this multivalent P. haemolytica vaccine is safe and stimulates marked antibody responses in bighorn sheep. Further evaluation of this vaccine as a tool in preventing and managing pasteurellosis in bighorn sheep appears warranted.

Duration of Immunity Induced by Commercially Available Pasteurella haemolytica Vaccines

Calves on range with their dams were vaccinated with 5 commercially available Pasteurella haemolytica vaccines in duration of immunity studies. Immunity was challenged at 83 and 97 days post-vaccination by transthoracic inoculation of virulent P haemolytica.

Effects of Trypanosoma evansi on the output of cells from a lymph node draining the site of Pasteurella haemolytica vaccine administration

The prefemoral efferent lymphatics of sheep infected with Trypanosoma evansi and inoculated with P. haemolytica vaccine and of those given only the vaccine, were surgically cannulated to study the effects of the infection on the total cellular output and output of blast cells from the node in response to the vaccine. T. evansi delayed and depressed the increases in total cell and lymphoblast outputs. In uninfected sheep, the total cellular output increased and peaked at more than twice the prevaccination values on days 4 and 5 after primary vaccination, but the increases were smaller and peaked on days 6 and 8 after primary vaccination in the infected sheep. The output of lymphoblasts mirrored the total cell output, though it was suppressed to a greater degree by T. evansi. The output of blasts peaked at more than 8 and 14 times the prevaccination values in the uninfected animals after primary and secondary (booster) vaccinations, respectively; but in infected animals, it peaked at twice the prevaccination values after the primary vaccination and showed no increase after booster vaccination until 11 days later. It is concluded that the inhibition of total and blast cell outputs by T. evansi may limit the early systemic dissemination of antigen-specific cells, thus playing a role in the induction of immunosuppression by the parasite.

Comparative evaluation of antibodies induced by commercial Pasteurella haemolytica vaccines using solid phase immunoassays

The objective of this study was to evaluate the ability of four commercial vaccines to elicit antibodies against the leukotoxin (Lkt), capsular polysaccharide (CP), iron regulated outer membrane proteins (IROMPs), and whole cell (WC) antigens of Pasteurella haemolytica A1. Modified double antibody sandwich enzyme linked immunosorbent assays (ELISAs) were developed to measure antibody levels against Lkt, CP and IROMPs. An indirect ELISA was developed to measure the levels of antibody against WC antigens. The ideal cut off points for ELISAs were determined on receiver operating characteristic curves, using sera from 30 calves injected subcutaneously with a live P. haemolytica 12296 strain as positive control and sera from 30 colostrum-deprived calves as negative control. The vaccines evaluated were: ‘One Shot’ (SmithKline Beecham, West Chester, PA) a bacterin-toxoid, ‘Presponse’ (Langford Laboratories, Guelph, Ontario) a Lkt-rich culture supernatant, ‘Once PMH’ (BioCor Inc., Omaha, NE) a modified live vaccine, and ‘Septimune’ (Fort Dodge laboratories, Fort Dodge, IA) an outer membrane extract. Thirty, 4–6 week old Holstein calves were randomized into 5 groups to receive one of the four vaccines or a placebo (sterile phosphate buffered saline). The calves were vaccinated intramuscularly on day 0 and on day 14, and bled on days 0, 14, and 28 to measure antibody levels against Lkt, CP, IROMPs, and WC antigens of P. haemolytica A1. ‘One Shot’, and ‘Once PMH’ vaccinates showed a significant ( P < 0.05) increase in antibody levels against Lkt at 28 days. ‘Once PMH’ vaccinates also showed significant ( P < 0.05) increase in antibody levels against IROMPs at 28 days compared to the other four groups but this increase was not significant over time within the ‘Once PMH’ group. ‘Presponse’, ‘Once PMH’, and ‘One Shot’ vaccinates showed a significantly ( P < 0.05) increase in antibody levels against CP over time. These groups also had significantly higher antibody levels against CP, compared to controls and ‘Septimune’ vaccinates at 14 and 28 days ( P < 0.05).

Evaluation of Pasteurella and Haemophilus Vaccines

The family Pasteurellaceae Pohl contains gramnegative, facultatively anaerobic and fermentative bacteria of the genera Pasteurella, Haemophilus, and Actinobacillus. Of these genera, Haemophilus somnus, Pasteurella multocida and Pasteurella haemolytica are prominent pathogens in domestic cattle causing severe diseases and major economic losses. Mechanisms of immunity to these bacteria have been difficult to determine, and efficacious vaccines have been a challenge to develop and evaluate.&#x0D; In this review, we will summarize current published data on antigens and immunity associated with H. somnus, P. multocida, and P. haemolytica. This will be followed by a discussion of experimental studies conducted in our laboratories using commercial P. haemolytica vaccines.

Supplemental chromium and bovine respiratory disease vaccines for stressed feeder calves

Performance, morbidity, serum Cortisol, plasma ascorbate (AsA) and serum tri-iodothyronine (T3) were evaluated in crossbred steer calves purchased at sales in Ontario. Thirty-three steers were randomly assigned to each of control; vaccination with Infectious Bovine Rhinotracheitis, Parainfluenza-3, Bovine Viral Diarrhea, and Bovine Respiratory Synctial Virus vaccine and P. haemolytica vaccine; 0.14 ppm supplemental chelated Cr; and Cr plus vaccines, for the 49 d trial. Supplemental Cr plus vaccine increased (P &lt; 0.05) daily gain and feed intake during the first 28 d. Furthermore, vaccination increased (P &lt; 0.05) 28 d gain for mid-performing steers. Vaccines, Cr and Cr plus vaccines did not reduce morbidity (P &gt; 0.05); however, the Cr-supplemented group had fewer relapses (P &lt; 0.05). Rectal temperature was reduced in both vaccinated and Cr-supplemented calves on days 10–16 post-arrival. Serum cortisol was reduced (P &lt; 0.05) in vaccinated calves and morbid Cr-supplemented calves on day 28 post-arrival. The ratio of free to total T3 on day 7 and day 14 post-arrival, and AsA on day 14 post-arrival was greater (P &lt; 0.05) for calves receiving supplemental Cr plus vaccines. Results confirm previous reports of the beneficial effect of Cr on performance, and indicate some additive effects of Cr and vaccines with respect to daily gain and plasma ascorbate. Key words: Chromium, vaccines, ascorbic acid, tri-iodothyronine, stress, calves

Disturbances in ex vivo vascular smooth muscle responses following exposure to Pasteurella haemolytica vaccines

Rats were vaccinated with saline (control) or one of the two commercially available Pasteurella haemolytica vaccines Presponse or Precon-PH. Animals were killed 3 days later and thoracic aorta removed for evaluation of the ex vivo biophysical responses to carbachol (CCh). In some experiments, vascular endothelium was mechanically removed. Vaccination of rats impairs the endothelial-dependent relaxation to CCh. In vessels with endothelium removed, the contractile response to CCh is converted into a relaxation following vaccination. Treatment of endothelial-denuded vascular rings ex vivo with methylene blue, a guanylate cyclase inhibitor, reduced the vaccination effect. Treatment of vascular rings with the superoxide dismutase inhibitor diethyldithiocarbamate, impairs the relaxant response of de-endothelialized vessels to CCh in Presponse vaccinated rats while enhancing the relaxation response of vessels from Precon-PH vaccinated rats. De-endothelialized vessels from vaccinated rats, but not control rats, relaxed in the presence of N-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of nitric oxide synthetase. Furthermore, in the presence of L-NMMA, the relaxant response to CCh is significantly enhanced by Precon-PH but not Presponse. The normal relaxant response to hydrogen peroxide is converted into a contraction following vaccination. Results suggest that exposure to commercially available P. haemolytica vaccines alters vascular smooth muscle reactivity to CCh and that several independent pathways may be altered.

Immunogens of Pasteurella

The family Pasteurellaceae Pohl contains Gram-negative, facultatively anaerobic and fermentative bacteria of the genera Pasteurella, Haemophilus, and Actinobacillus. Approximately 20 different species of the genus Pasteurella have been identified using phenotypic and genetic analyses. Of these species, P. multocida and P. haemolytica are the most prominent pathogens in domestic animals causing severe diseases and major economic losses in the cattle, swine, sheep, and poultry industries. Mechanisms of immunity to these bacteria have been difficult to determine, and efficacious vaccines have been a challenge to develop and evaluate. Pasteurella multocida of serogroups A and D are mainly responsible for disease in North American poultry and pigs and to a lesser extent in cattle. Fowl cholera in chickens and turkeys is caused by various serotypes of P. multocida serogroup A and characterized by acute septicemia and fibrinous pneumonia or chronic fibrinopurulent inflammation of various tissues. Current biologicals in use are live P. multocida vaccines and bacterins. Potency tests for avian P. multocida biologicals are a bacterial colony count for vaccines and vaccination and challenge of birds for bacterins. Somatic antigens, particularly lipopolysaccharide (LPS), appear to be of major importance in immunity. In North American cattle, P. multocida serogroup A is associated mainly with bronchopneumonia (enzootic pneumonia) in young calves; however, it is occasionally isolated from fibrinous pleuropneumonia of feedlot cattle (shipping fever). Biologicals currently available are modified-live vaccines and bacterins. The potency test for vaccines is bacterial colony counts. The test for bacterin potency is vaccination and challenge of mice. Important immunogens have not been well characterized for P. multocida infection in cattle. In swine, P. multocida infection is sometimes associated with pneumonia; however, its major importance is in atrophic rhinitis. A protein toxin (dermonecrotic toxin), produced by toxigenic strains of P. multocida types A and D, and concurrent infection with Bordetella bronchiseptica appear to be the major factors in development of atrophic rhinitis. Currently available biologicals are bacterins and inactivated toxins (toxoids). The toxin appears to be to be the major immunogen for preventing atrophic rhinitis. There are, however, no standardized requirements for potency testing of P. multocida type D toxoid. Various serotypes of P. haemolytica biotype A are responsible for severe fibrinous pleuropneumonia of cattle and sheep, occasionally septicemia of lambs, and mastitis in ewes. Several serotypes of P. h haemolytica biotype T are isolated from acute septicemia of lambs. The currently available P. haemolytica biologicals are modified-live vaccines, bacterins, bacterial surface extracts, and culture supernates that contain an exotoxin (leukotoxin). Most biologicals contain P. haemolytica biotype A serotype 1; however, biotype T serotypes 3 and 4 are occasionally included. As with P. multocida vaccines, the potency test for a P. haemolytica vaccine is a bacterial colony count. There are no standard guidelines for potency tests for P. haemolytica bacterins or extracts and supernate biologicals. The major immunogens for P. haemolytica appear to be the leukotoxin, capsule, outer membrane proteins, and iron-regulated proteins.

Variation of abscess formation in cattle after vaccination with a modified-live Pasteurella haemolytica vaccine

Summary During the spring of the first year of a vaccine study, 57 of 238 calves (24%), in which modified-live Pasteurella haemolytica vaccine (mlv) was injected twice, developed 1 or more abscesses. Abscesses were not observed after multiple visual examinations of 437 calves given killed P haemolytica bacterin or placebo injections of similar adjuvants used in the vaccine and bacterin. Calves that developed abscesses after the second injection of mlv weighed significantly (P &lt; 0.05) less (on the basis of body weight adjusted for weaning weight) at the second injection than did those that did not develop abscesses. Compared with calves given mlv that did not develop observable abscesses, calves developing abscesses after the second injection of mlv weighed 11.0 and 14.2 kg less, respectively, at 56 days and 112 days after injection, and they had 11.0 kg less gain at 56 days after injection. Abscess prevalence tended to be highest on certain days or at certain locations used for cattle processing, and the prevalence of abscesses increased in cattle processed later on a given day. Abscesses were not observed in 2 other groups of similarly treated calves vaccinated in the autumn or in the subsequent spring.

Vaccine-derived Pasteurella haemolytica alter the responses of ovine pulmonary artery and vein to drugs acting on adenylate cyclase

Sheep were vaccinated with a live, vaccine-derived strain of Pasteurella haemolytica. The ex vivo response of isolated pulmonary artery and vein to isoproterenol, cholera toxin, sodium fluoride and calcium were examined three days after vaccination. In the pulmonary artery (endothelium intact), vaccination did not alter the response to isoproterenol, or sodium fluoride whereas the relaxation response to cholera toxin was impaired. In the pulmonary artery (endothelium removed), the maximum relaxation attained in response to isoproterenol was reduced and the response to exogenous calcium, sodium fluoride and cholera toxin not altered. In the pulmonary vein (endothelium intact), the response to isoproterenol and sodium fluoride was unchanged whereas the response to cholera toxin was impaired. In the pulmonary vein (endothelium removed), the response to isoproterenol and sodium fluoride was not altered following P haemolytica vaccination whereas the relaxation response to cholera toxin was enhanced and the response to exogenous calcium slightly impaired. These experiments suggest that vaccination with live strains of P haemolytica cause subclinical disturbances in the pulmonary circulation and may potentially alter the animals' response to pathogens.

Effect of Presponse® on the gain and health of long-hauled, newly arrived calves (1992)

Five hundred mixed-breed steer and bull calves (246 lbs) were divided into two treatment groups, with one group receiving a new Pasteurella haemolytica vaccine (Presponse®) at arrival. There was no difference between groups in terms of gain, mortality, or morbidity during the 32-day receiving study. The Presponse group required fewer (P<.09) medication days per animal purchased, resulting in $1.68 less drug cost per head than the control group.

Development of pneumonia in desert bighorn sheep after exposure to a flock of exotic wild and domestic sheep

Summary 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. Pasturella 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 α 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. The bighorn sheep was vaccinated with a modified-live Pasteurella haemolytica vaccine and allowed to habituate to its new facilities for 133 days before it was exposed to the carrier sheep. Body temperature of this bighorn sheep was monitored every hour with radiotelemetry. Pneumonia was diagnosed on day 30 of exposure to the carrier sheep. Treatment consisting of long-acting oxytetracycline, sulfadimethoxine, long-acting sulfamethazine bolus, dexamethasone, and flunixin meglumine was given for 8 days and clinical improvement was detected. Acute pneumonia was again diagnosed on day 53. The bighorn sheep was removed from contact with the carrier sheep and put in isolation for a second treatment regimen. The bighorn sheep died on day 99. Pasteurella multocida was isolated from a tracheal flush and a nasal specimen obtained during the second bout of pneumonia and from lung tissue and sinuses at necropsy. Viruses were not isolated from the tracheal flush or from tissue samples collected at necropsy. None of the carrier sheep had clinical signs of pneumonia during the trials. Bacteriologic culturing and serologic testing in the bighorn sheep and ewes prior to and during the study suggested that carrier ewes were the source of P multocida infection in the bighorn sheep. Viruses were not a predisposing factor. Chronic sinusitis following initial pneumonia was suspected to play a role in the recurrence of pneumonia in the bighorn sheep of trial 5.

Immune response of neonatal lambs to a modified live Pasteurella haemolytica vaccine

Pregnant cross-bred ewes in the last month of gestation were either inoculated once intradermally with 0.5 ml of a modified-live Pasteurella haemolytica vaccine ( n=26) or kept as non-vaccinated controls ( n=24). Serum was collected at that time and 2 weeks later for evaluation of P. haemolytica antibodies. Vaccinated ewes were reinoculated at 2 week intervals until lambing. Vaccinated ewes responded 2 weeks after a single inoculation with a small but statistically significant increase in direct bacterial agglutination (DBA) log 2 titer (4.9 to 5.3). Control ewe titers did not increase. Lambs born to all ewes in the study received colostrum from their dams. Approximately equal number of randomly selected lambs from both ewe groups were serologically evaluated for P. haemolytica DBA and leukotoxin serum antibody titers on day 2 of life. Lambs from vaccinated ewes showed no significant increase in DBA titers (4.5 vs 3.9) but had significantly elevated anti-leukotoxin titers (3.5 vs 2.2) compared to lambs from control ewes. These same lambs were then assigned to either a vaccination or a non-vaccination group. Vaccination group lambs were inoculated intradermally on days 2 and 16 of life with 0.25 ml of the same vaccine given the ewes. Lambs were bled on days 16, 23, 30, 37, and 60, and sera were assayed for DBA and leukotoxin antibody titers. In addition, randomly selected sera from bleeding days 2, 16, 23, and 30 were screened for antibody against a carbohydrate-protein subunit of P. haemolytica using ELISA. Vaccination of lambs from both ewe groups resulted in increased DBA titers on days 23 and 30 compared to controls. Thereafter, titers increased in all groups, and there were no differences between them on day 60. Vaccination of lambs did not affect leukotoxin antibody. Lambs from vaccinated ewes, however, had significantly lower anti-leukotoxin titers than lambs from non-vaccinated ewes by day 60. There was no effect of lamb vaccination on carbohydrate-protein subunit antibody. This study did not assess efficacy of the vaccine against challenge; however, based on serological responses, vaccination of lambs with a modified-live Pasteurella haemolytica vaccine does not appear to be an efficacious preventative strategy for ovine enzootic pneumonia.