Source: TEXAS A&M UNIVERSITY submitted to NRP
EVOLVING PATHOGENS, TARGETED SEQUENCES AND STRATEGIES FOR CONTROL OF BOVINE RESPIRATORY DISEASE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0157783
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
NC-107
Project Start Date
Oct 1, 2001
Project End Date
Sep 30, 2006
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
TEXAS A&M UNIVERSITY
750 AGRONOMY RD STE 2701
COLLEGE STATION,TX 77843-0001
Performing Department
VETERINARY PATHOBIOLOGY
Non Technical Summary
Mass antibiotic treatment of stocker-feeder calves (metaphylaxis) for the control of bovine respiratory disease complex is widely used. However, timing of metaphylaxis is critical for success. Dual prophylaxis, which combines immunoprophylaxis (vaccination) with metaphylaxis reduces disease incidence and severity in controlled laboratory studies, addresses the problem of antibiotic resistance, and explores the importance of a new viral cause, respiratory bovine coronavirus.
Animal Health Component
40%
Research Effort Categories
Basic
30%
Applied
40%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3113399109060%
3113499110340%
Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3499 - Dairy cattle, general/other; 3399 - Beef cattle, general/other;

Field Of Science
1090 - Immunology; 1103 - Other microbiology;
Goals / Objectives
(1) Identify emerging and re-emerging agents and develop diagnostic methods for BRD. (2) Characterize mechanisms and intervention targets in pathogenesis of BRD at the molecular, cellular and host level. (3) Develop intervention strategies for critical control points to reduce impact of BRD.
Project Methods
With collaborating order buyers(s), backgrounder(s), and calf feeder(s) the benefits of combined antibiotic and vaccine prophylaxis (dual prophylaxis) in high risk calves will be compared to antibiotic prophylaxis (metaphylaxis). The following parameters will be analysed: incidence of pneumonia, severity of disease, carcass grade at slaughter, average daily gain, total amount of antibiotic used, and profit (loss) at slaughter. High risk calves will be purchased from local auction markets in eastern Tennessee. These will be assembled and processed as truckload units and shipped to collaborating backgrounder, stocker and feeder operations. Processing of truckload units sent to each destination will be alternated between preshipment dual prophylaxis or post-shipment metaphylaxis. Dual prophylaxis will be with Mannheimia haemolytica/ Pasteurella multocida mixed bacterin and simultaneous metaphylaxis with tilmicosin phosphate at the first preshipment point of assembly. Metaphylaxis will be with tilmicosin phosphate given postshipment. Health data, total antibiotic use and average daily gain will be obtained from all participants. Carcass grades and profit (loss) will be obtained from participating feedyard(s). The risk of inducing antibiotic resistance by metaphylaxis and dual prophylaxis will be evaluated in both target and nontarget bacterial flora of the stocker-feeder calves in the drainage system and downstream playas of feedyards; and in feedyard workers. For this study the target bacteria for the tilmicosin antibiotic, Mannheimia haemolytica, will be isolated from sick and dead calves. Mannheimia haemolytica will be tested for the emergence of antibiotic resistance patterns over the length of the study. The non target bacteria to be tested for developing antibiotic resistance will be Pasteurella multodica isolated from the respiratory tracts of sick and dead calves, and Salmonella and Escherichia isolated from the enteric tracts of calves exiting backgrounding operations. Non-target Salmonella sp. and Escherichia sp. in animal caretakers in close contact with tilmicosin phosphate treated calves will also be examined for tilmicosin resistance. Antibiotic resistance will be characterized as to type; likelihood of transmission to non-target bacterial species and overlapping bacterial resistance patterns with other macrolide antibiotcs, e.g. erthromycin. In other studies on the cause of bovine respiratory disease complex serum samples will be collected from stocker-feeder calves at the first point of assembly. These samples will be tested for specific antibody to respiratory bovine coronavirus by hemagglutination inhibition and serum neutralization assays. Only those infected on the farm of the origin would be expected to have antibody at this time; thus antibody specific for the respiratory bovine coronavirus will give an approximation of the incidence of this virus infection in the national cattle population. Based on these studies of the incidence of respiratory bovine coronavirus the cost effectiveness of immunoprophylaxis will be estimated.

Progress 10/01/01 to 09/30/06

Outputs
The prevention of bovine respiratory disease complex (BRDC) by simultaneous Mannheimia-Pasteurella vaccination and metaphylaxis with long acting antibiotic formulations (dual prophylaxis) at first point of assembly of 400 to 500 lb. high-risk stocker-feeder calves was evaluated. Two field studies of approximately balanced, randomized block design were conducted. Dual prophylaxis treatment with Mannheimia haemolytica-Pasteurella multocida bacterin-toxoid and metaphylaxis with tilmicosin compared to metphylaxis treatment with tilmicosin alone resulted in a significant reduction in calves requiring two or more therapeutic regimens (retreatments) for BRDC during the subsequent 28 day receiving period (11/48 vs. 28/60; p<0.025). In the second study, dual prophylaxis with M. haemolytica-Pasteurella multocida bacterin-toxoid and tilmicosin treatment, resulted in significantly fewer calves developing BRDC during a 45-day backgrounding period compared to therapeutic intervention as sickness occurred (pull and treat health management) (9/69 vs. 35/69; p<0.01). Dual prophylaxis, with M. haemolytica-P. multocida bacterin-toxoid and oxytetracline treatment, compared to pull and treat management also resulted in significantly fewer calves developing BRDC during backgrounding (16/68 vs. 35/69; p<0.01). Differences in BRDC morbidity in calves receiving dual prophylaxis with tilmicosin or oxytetracycline were not significant. The overall cost of dual prophylaxis with oxytetracycline and subsequent necessary BRDC therapy in the feedyard was less than the cost of the therapy for BRDC with pull and treat health management. Also, calves receiving dual prophylaxis gained more than those managed by the pull and treat method as determined at slaughter.

Impacts
Dual Prophylaxis in high risk calves has the potential to significantly reduce sickness, during the receiving and backgrounding period. These health benefits could markedly reduce the need for feed-grade antibiotics during the receiving period and the associated dangers of developing antibiotic resistant bacterial populations in calves.

Publications

  • No publications reported this period


Progress 01/01/03 to 12/31/03

Outputs
The prevention of bovine respiratory disease complex (BRDC) by simultaneous Mannheimia-Pasteurella vaccination and metaphylaxis with long acting antibiotic formulations (dual prophylaxis) at first point of assembly of 400 to 500 lb. high-risk stocker-feeder calves was evaluated. Two field studies of approximately balanced, randomized block design were conducted. Dual prophylaxis treatment with Mannheimia haemolytica-Pasteurella multocida bacterin-toxoid and metaphylaxis with tilmicosin compared to metphylaxis treatment with tilmicosin alone resulted in a significant reduction in calves requiring two or more therapeutic regimens (retreatments) for BRDC during the subsequent 28 day receiving period (11/48 vs. 28/60; p<0.025). In the second study, dual prophylaxis with M. haemolytica-Pasteurella multocida bacterin-toxoid and tilmicosin treatment, resulted in significantly fewer calves developing BRDC during a 45-day backgrounding period compared to therapeutic intervention as sickness occurred (pull and treat health management) (9/69 vs. 35/69; p<0.01). Dual prophylaxis, with M. haemolytica-P. multocida bacterin-toxoid and oxytetracline treatment, compared to pull and treat management also resulted in significantly fewer calves developing BRDC during backgrounding (16/68 vs. 35/69; p<0.01). Differences in BRDC morbidity in calves receiving dual prophylaxis with tilmicosin or oxytetracycline were not significant. The overall cost of dual prophylaxis with oxytetracycline and subsequent necessary BRDC therapy in the feedyard was less than the cost of the therapy for BRDC with pull and treat health management. Also, calves receiving dual prophylaxis gained more than those managed by the pull and treat method as determined at slaughter.

Impacts
Dual Prophylaxis in high risk calves has the potential to significantly reduce sickness, during the receiving and backgrounding period. These health benefits could markedly reduce the need for feed-grade antibiotics during the receiving period and the associated dangers of developing antibiotic resistant bacterial populations in calves.

Publications

  • Chirase, N. K., Purdy, C., W., Green, L. W., Loan, R. W., Briggs, R., Duff, G., Avanipato, J. and Murray, D. The effect of transport stress on respiratory disease, serum oxidant status and lipoperoxidation levels in beef cattle. AJVR. Accepted August 28, 2003.


Progress 01/01/02 to 12/31/02

Outputs
In controlled field studies of bovine respiratory disease complex (BRDC) the predominant identified viral infections were infectious bovine rhinotracheitis, parainfluenza 3, bovine viral diarrhea, bovine adenovirus and respiratory bovine coronovirus. Seroconversions to these viruses occurred in both sick and well calves. When these viruses were associated with calf pneumonia or death; however, Mannheimia haemolytica, biotype A, serotype 1 and/or Pasteurella multocida were the common bacterial pathogens isolated and the lesions in dead calves were consistent with these infections. In further studies prevention of these bacterial infections by simultaneous vaccination and prophylactic antibiotic medication (dual prophylaxis) increased the number of well calves by 70 percent and decreased the number of calves with severe (recurrent) BRDC by 51 percent. Additional field studies in 2002 indicate that dual prophylaxis with either tilmicosin or oxytetracycline significantly reduced the incidence of BRDC during the 45 day receiving period and increased weight gain during the same period by 30 to 35 percent compared to controls.

Impacts
Dual prophylaxis in high risk assembled calves has the potential to reduce sickness, improve average daily gain, increase carcass quality and increase profit upwards of $20 per calf. By preventing rather than treating sickness, the risk of antibiotic resistant bacteria developing in chronically infected and retreated calves may also be lessened.

Publications

  • Frank G, Briggs R, Duff G, Loan R, Purdy C. 2002. Effects of vaccination prior to transit and administration of florfenicol at time of arrival in a feed lot on the health of transported calves and detection of Mannheimia haemolytica in nasal secretions. AJVR 63(2):251-256.
  • Fulton RW, Ridpath JF, Saliki JT, Briggs RE, Confer AW, Burge LJ, Purdy CW, Loan RW, Duff GC, Payton ME. 2002. Bovine viral diarrhea virus (BVDV)1b: Predominant BVDV subtype in calves with respiratory disease. Canadian Jr. Vet. Res. 66:181-190.
  • Fent GM, Fulton RW, Saliki JT, Caseltine SL, Lemkuhl HD, Confer AW, Purdy CW, Briggs RE, Loan RW, Duff GC. 2002. Bovine adenovirus-7 infections in post-weaning calves. AJVR 63(7):976-978.


Progress 01/01/01 to 12/31/01

Outputs
In controlled field studies of bovine respiratory disease complex (BRDC) the predominant identified viral infections were infectious bovine rhinotracheitis, parainfluenza 3, bovine viral diarrhea, bovine adenovirus and respiratory bovine coronovirus. Seroconversions to these viruses occurred in both sick and well calves. When these viruses were associated with calf pneumonia or death; however, Mannheimia haemolytica, biotype A, serotype 1 and/or Pasteurella multocida were the common bacterial pathogens isolated and the lesions in dead calves were consistent with these infections. In further studies prevention of these bacterial infections by simultaneous vaccination and prophylactic antibiotic medication (dual prophylaxis) increased the number of well calves by 70 percent and decreased the number of calves with severe (recurrent) BRDC by 51 percent.

Impacts
Dual prophylaxis in high risk assembled calves has the potential to reduce sickness, improve average daily gain, increase carcass quality and increase profit upwards of $20 per calf. By preventing rather than treating sickness, the risk of antibiotic resistant bacteria developing in chronically infected and retreated calves may also be lessened.

Publications

  • No publications reported this period


Progress 01/01/00 to 12/31/00

Outputs
In a controlled field study of bovine respiratory disease complex (BRDC), earlier findings of benefits from vaccination for Pasteurella pneumonia with metaphylaxis (prophylactic mass medication) were confirmed. One hundred-twenty calves were medicated with mycotil (timicosin phosphate) at the first point of assembly (order buyer barn). One-half of the calves were vaccinated with a combination Pasteurella (Mannheimia) haemolutica and Pasteurella multocida bacterin. As compared to metaphylaxis alone, vaccination resulted in significant reduction in calf morbidity and mortality (p less than 0.01) and number of sick days (p less than 0.025). This was accompanied by a reduction in antibiotic treatments during the receiving period (1.16 vs. 0.68 treatments per calf). Vaccination also resulted in significant increases in average daily gain and total gain. A conservative estimate of the cost-benefit of vaccination in this high-risk shipment of assembled calves was 22 dollars per calf.

Impacts
(N/A)

Publications

  • Frank, GH, Briggs, RE, Loan, RW, Purdy, CW, Zehr, ES. 2000. Effects of tilmicosin treatment of Pasteurella haemolytica organisms in nasal secretion specimens of calves with resporatory tract disease. Am. Jr. Vet. Res. 61:525-529.
  • Purdy, CW, Loan, RW, Straus, DC, Briggs, RE, Frank, GH. July 2000. Conglutinin and immunoconglutinin activity in stressed feeder calves. Accepted, Amer. Journ. Vet. Res.
  • Storz, J, Lin, XQ, Purdy, CW, Chouljenko, VN, Kousoulas, KG, Gilmore, WC, Enright, FM, Corstvet, RE, Briggs, RE, Loan, RW. 2000. Coronavirus and Pasteurella infections in bovine shipping fever pneumonia and Evans' criteria of causation. Jr. Clin. Microbiol. 38:3291-3298.
  • Lin, XQ, O'Reilly, KL, Story, J, Purdy, CW, Loan, RW. August 2000. Antibody responses to respiratory coronavirus infections of cattle during a shipping fever epizootic. Accepted, Journal of Virology.
  • Fulton, RW, Purdy, CW, Confere, AW, Saliki, JT, Loan, RW, Briggs, RE, Burge, LJ. 2000. Bovine viral diarrhea viral infections in feeder calves with respiratory disease; Interaction with Pasteurella spp., parainfluenza-3 virus and bovine respiratory syncytial virus. Canada Jrn. Vet. Res. 64:151-159.
  • Storz, J, Lin, XQ, Chouljenko, VN, Kousoulas, KG, Purdy, CW, Loan, RW, Enright, FM. 2000. Respiratory coronaviruses and Pasteurella haemolytica in shipping fever pneumonia of cattle. 100th Gen. Mtg. Am. Soc. for Microbiology, Los Angeles, CA, May 21-25, Abstract.
  • Fulton, RW, Saliki, JT, Confer, AW, Burge, LJ, PurdyCW, Briggs, RE, Duff, GC, Loan, RW. 2000. Bovine viral diarrhea virus infections in calves from auction markets and a ranch. Assm American Vet. Lab. Diagnosticians, Birmingham, Ala., October 19-26, Abstract.
  • Chirase, NK, Greene, LW, Purdy, CW, Auvermann, BW, Loan, RW, Parker, DB, Hoover, MD. May 2000. Influence of simulated feedyard dust on performance of market-stressed steer calves protected with or without prophylactic antibiotic. Joint abstracts of the Am. Dairy Science and Soc. of Animal Science. Abstract.
  • Purdy, CW, Loan, RW, Straus, DC, Chirase, NK, Briggs, RE, Duff, GC, Hoover, MD. Nov. 2000. Effects of feedyard dust and endotoxin on market stressed feeder calves. 81st Ann. Mtg. Conf. Res. Workers An. Dis., Chicago, IL, Abstract.
  • Storz, J, Purdy, CW, Lin, XQ, Burrell, M, Truax, RE, Briggs, RE, Frank, GH, Loan, RW. 2000. Isolation of respiratory bovine coronavirus, other cytodical viruses and Pasteurella spp. from cattle involved in two natural outbreaks of shipping feaver, JAVMA 216:1599-1604.


Progress 01/01/99 to 12/31/99

Outputs
Pasteurella haemolytica A1 Bacterin-Toxoid (Leukotox(TM)) licensed to American Aimal Health Inc., Grand Prarie, Texas continues to have reduced sales due to poor cattle markets and vaccine industry competition. During the past year, Dr. Loan assisted in developing a challenge method for immunity to P. multocida. New combined and one-dose formulations resulting from this shoul improve market share.

Impacts
(N/A)

Publications

  • No publications reported this period


Progress 01/01/98 to 12/31/98

Outputs
In a controlled field study of bovine respiratory disease complex BRDC in October 1997 an experimental Pasteurella haemolytica A1 extract bacterin, administered intravenously at the first point of assembly of calves, stimulated rapid immune responses, but did not alter the incidence of BRDC. However, intercurrent infections by a highly pathogenic respiratory bovine coronavirus, RBCV, not previously associated with epidemic BRDC, occurred. Further ongoing research based on this controlled field study include 1 the sequencing of bovine interferon genes with correlations back to clinical disease, 2 glucocorticosteroid levels and clinical disease, 3 the effect of feedlot dust on BRDC no effect found thus far, 4 the ecology and epidemiology of P. haemolytica, 5 the efficacy of tilmycosin for the treatment of BRDC it is highly efficaceous and reduces nasal colonization and 6 comparison of the nucleotide sequence of the RBCV to bovine enteric cornoavirus. Other related studies include 1 the release of interleukins by antigen stimulated pulmonary alveolar macrophages and 2 the effect of the microenvironment on bacterial enzyme activity. In this latter study, low level antibiotics cause marked alteration in enzyme systems of antibiotic resistant P. haemolytica. A repeat of the above controlled field was conducted in October, 1998 with similar clinical and early diagnostic laboratory results. These studies add further credibility to the concept that RBCV plays an important role in BRDC and that new vaccination regimes combined with early antimicrobial prophylaxis and therapy will markedly reduce losses due to BRDC.

Impacts
(N/A)

Publications

  • Briggs, R. E., Frank, G. H., Purdy, C. W., Zehr, E. S. Loan, R. W. 1998. Rapid spread of a unique plasmid of Pasteurella haemolytica serotype 1 among shipped calves. AJVR 59:401-405.
  • Loan, R. W., Tung, H. T., Payne, J. B. 1998. Comparative efficacy and duration of immunity of commercial Pasteurella haemolytica vaccines. Bovine Pract.: 18-21.
  • Straus, D. C., Purdy, C. W., Loan, R. W., Briggs, R. E. 1998. In vivo production of neuraminidase by Pasteurella haemolytica in market stressed cattle. Current Microbiology. Accepted May .
  • Purdy, C. W., Straus, D.C., Loan, R. W., Briggs, R., Parker, J. D., Auvermann, B., Chirase, N., Storz, J., Williams, P. B. 1998. Analysis of endotoxin in feedyard air and playas. High Plains Beef Conference. Canyon, Texas, August 26-27, 1998. Manuscript accepted.
  • Straus, D. C., Purdy, C. W., Loan, R. W., Briggs, R. F., Frank, G. H. 1998. In vivo production of neurominidase by Pasteurella haemolytica in cattle following natural infection. 98th ASM Meeting, May 17-21, 1998. Atlanta. Abstract.
  • Purdy, C. W., Loan, R. W., Briggs, R., Frank, G. H., Storz, J., Parker, P., Auvermann, B., Chirase, N. 1998. Market-stressed calves exposed to endotoxin in organic dust. Conf. Res. Workers An. Dis., Chicago, Ill., Nov. 9-10, 1998. Abstract.
  • Storz, J., Purdy, C. W., Briggs, R. E., Lin, X. Q., Burrell, M., Loan, R. W. 1998. Market-stressed cattle of a shipping fever epizootic in a Texas feedlot have a high infection rate with respiratory bovine coronavirus. 31st Ann. Conf. Of Am. Assn. Bov. Practi., Spokane, Washington, Sept. 22-23, 1998. Abstract.
  • Storz, J., Purdy, C. W., Lin, X. Q., Burrell, M., Briggs, R. E., Loan, R. W. 1998. Dynamics of virus infections in a severe shipping fever epizootic of market-stressed cattle. Conf. Res. Workers An. Dis., Chicago, Ill., November 8-10, 1998. Abstract.
  • Storz, J., Purdy, C. W., Lin, X. Q., Gilmore, W. C., Corstvet, R. E., Enright, F. M., Loan, R. W., Briggs, R. E. 1998. Respiratory coronavirus and Pasteurella hemolytica infections in fatal pneumonia of cattle. Conf. Res. Workers in An. Dis., Chicago, Ill., November 8-10, 1998. Abstract.
  • Frank, G. H., Briggs, R. E., Loan, R. W., Purdy, C. W., Zehr, E. S. 1998. Effect of tilmycosin on colonization of the nasal passages of cattle by Pasteurella haemolytica of cattle undergoing respiratory disease. In final stages of preparation.
  • Purdy, C. W., Straus, D. C., Frank, G. H., Briggs, R. E., Loan, R. W. 1998. Conglutinin and immunoconglutinin activity of market-stressed calves. Manuscript in preparation.


Progress 01/01/97 to 12/31/97

Outputs
The comparative duration of immunity following vaccination with five widely used commercially available Pasteurella haemolytica vaccines was compared in 60 nursing calves. Duration of immunity was determined by survival and lung lesion size following transthoracic challenge of immunity at 83 and 97 days postvaccination. There were significant differences in duration of protection compared to nonvaccinated controls. Overall, vaccination with two of the bacterin-toxoids gave the best protection. A streptomycin-dependent live vaccine gave no protection. These studies indicate the value of specific vaccines for use in on-the-farm early calfhood vaccination programs for the prevention of bovine respiratory disease in the feedlot. In other studies it was determined that upon entering the feedlot 96 percent of the calves developed anti- neuraminidase antibody. This suggests the production of neuraminidase in vivo as a result of widespread Pasteurella haemolytica infections. A recent (October 1997) shipment of calves from Tennessee to Texas resulted in a severe outbreak of bovine respiratory disease. A respiratory coronavirus was isolated from over 60 percent of the calves. This finding strongly suggests a previously unrecognized important etiologic role for the bovine coronavirus in bovine respiratory disease complex.

Impacts
(N/A)

Publications

  • Briggs, R.E., G.H. Frank, E.S. Zehr, C.W. Purdy, R.W. Loan. 1997. Rapid spread of a unique plasmid of Pasteurella haemolytica serotype 1 among shipped calves. AJVR
  • Loan, R.W., H. Tung, J.B. Payne. November 10-11, 1997.Duration of immunity from commercially available Pasteurella haemolytica vaccines. Proc. 78th Ann. Meet. Conf. Res. Workers Anim. Dis.
  • Loan, R.W., H. Tung, J.B. Payne.September 18-21, 1997. Research Summary. Duration of immunity induced by commercially available Pasteurella haemolytica vaccines. Proceedings, American Association of Bovine Practitioners, pp. 151.


Progress 01/01/96 to 12/30/96

Outputs
An indirect competitive ELISA was standardized and optimized for the detection of Pasteurella haemolytica biotype A, serotype 1 (PhA1) antibodies. Upon challenge of immunity the ELISA antibody titers of calves that died with significantly lower than the titers of calves that survived challenge. The results indicate that a marked antibody response to the capsular antigens of PhA1 is correlated with resistance to pasteurella pneumonia. Geometric mean conglutinin (K) and immuno-conglutinin (IK) serum activities in 101 light-weight feeder calves were determined from serial serum samples. the calves were reared on four Tennessee farms. Samples were obtained on the farms of origin (FM), at an order-buyer barn (OBB) and weekly for 4 weeks in a USDA-ARS feedyard (FY) located in Bushland, Texas. One-half of the calves were vaccinated for PhA1 with an experimental vaccine. After arrival at the feedyard, 73 calves dveloped bovine respiratory disease (BRD) within 2 weeks and were treated with antibiotics. One calf died of BRD on FY day 4. Many PhA1 (n=311) and P. haemolytica biotype A, serotype 6 (n=122) were cultured from nasal turbinates and tonsilar crypts. K activity of calves was significantly (P 0.01) different on different farms and at the OBB compared to the farms of origin (P 0.001). Significant differences were not seen for K or IK activity between sick and healthy calves, heifers and steers, or between PhA1 vaccinates and non vaccinates.

Impacts
(N/A)

Publications

  • Loan, R.W., Payne, J.B., Tung, H. 1997. Studies of Six Commercially Available Pasteurella haemolytica Vaccines: Protective Immunity. In preparation.
  • Frank, G.H., R.E. Briggs, R.W. Loan, C.W. Purdy and E.S. Zehr. 1996. Respiratory Tract Disease and Mucosal Colonization by Pasteurella haemolytica in Transported Cattle. Am J Vet Res, 57, 1317-1320.
  • Sewell, Julie E. 1996. Development of an Indirect competitive ELISA for the Detection of Protective Antibodies in Pasteurella Pneumonia. Thesis submitted in partial fulfillment of the requirements for the Master of Science degree, Texas A&M
  • Purdy, C.W., Straus, D.C., Frank, G.H., Briggs, R.E. and Loan, R.W. 1996. Conglutinin and Immuno-Conglutinin Activity of Market Stressed Feeder Calves. Conf. Res. Workers in Animal Dis; Chicago, Illinois; November 1-12, Abstract #143.
  • Purdy, C.W., D.C. Straus, G.H. Frank, R.E. Briggs, and R.W. Loan. 1997. Conglutinin and Immuno-Conglutinin Activity of Market Stressed Feeder Calves. In Preparation.


Progress 01/01/95 to 12/30/95

Outputs
Objective 1. The incidence of respiratory tract disease was significantly related to farm of origin and was inversely proportional to Pasteurella haemolytica, biotype A, serotype 1 (PhA1) specific antibody titers at the time of assembly from farms of origin. There was also a high incidence of PhA6 on one farm which spread to calves from other farms during the feedlot receiving period. Objective 2. Analyses of the results of a 1994 shipment of feeder calves from Tennessee to Texas have been completed. This study confirmed earlier studies suggesting that vaccination with PhA1 reduced PhA1 colonization of the upper respiratory tract. Objective 3. There were significant differences in conglutinin and immunoconglutinin levels between farms of origin and an association between PhA1 indirect hemagglutination antibody (IHA) titers and conglutinin titers at the first point of assembly of calves.

Impacts
(N/A)

Publications


    Progress 01/01/94 to 12/30/94

    Outputs
    Vaccination of cattle with a cell culture-derived Pasteurella haemolytica serotype 1 bacterin elicited a serotype specific inhibition of nasal and tonsillar colonization by the homologous serotype in calves subsequently assembled and shipped. In a repeat of this experiment, calves from several herds were vaccinated and processed on farms near Newport, Tennessee, the week of June 19, 1994. Sequential serum, nasal and tonsillar samples, taken on the farm, in the stimulated market channel and in the feedlot were obtained and are being analyzed for specific antibody, conglutinin and P. haemolytica colonization. An enzyme-linked immunosorbent assay has been developed for serotype specific antigens of P. haemolytica. Using this test, the kinetics of immune responses also are being determined.

    Impacts
    (N/A)

    Publications


      Progress 01/01/93 to 12/30/93

      Outputs
      In a field study involving 128 comingled calves, frequent transmission of Pasteurella haemolytica, serotype 1, (identified by plasmid profile and by a rare deletion of the 4.1 kb cryptic plasmid) occurred within six days. Vaccination of calves with an experimental P. haemolytica, serotype 1 bacterin in oil adjuvant, from bacteria cultured in a simulated lung environment, elicited serotype-specific inhibition of nasal and tonsilar colonization by P. haemolytica. This bacterin also prevented death due to Pasteurella pneumonia in 4 of 6 calves vaccinated one-time 3 months previously.

      Impacts
      (N/A)

      Publications


        Progress 01/01/92 to 12/30/92

        Outputs
        Pasteurella haemolytica serotypes 1 and 2 have ben characterized according to enzyme and antibiotic resistance profiles. Serotype 1 isolates from the nasal cavities of 103 market stressed calves were classified by these methods into 20 biovars. Serotype 2 isolates were classified into 10 biovars. In further in vitro studies the biovar classifications appear to be relatively stable and the technique appears to be useful for epidemiologic studies. Studies of the transmission of P. haemolytica between cohabitating calves using stable biological markers is underway. In fermenter cultures, Pasteurella haemolytica colony forming output was increased up to 10 fold by modifications of culture media and environments. In field protection studies based on the above technology, vaccination on-the-farm with a Pasteurella haemolytica bacterin-toxoid very significantly reduced the incidence of nasal carriers of P. haemolytica.

        Impacts
        (N/A)

        Publications

        • LOAN, R.W., TIGGES, M.G., FARIES, F.C., and PURDY, C.W. 1992. On-the-farm management practices for preventing BRD. Veterinary Medicine (Food Animal Practice). October: 1038-1045.
        • PURDY, C.W., SCANLAN, C.M., LOAN, R.W., and FOSTER, G.S. 1992. An epidemiological study of Pasteurella haemolytica in market-stressed feeder calves: isolates identified by enzyme and antimicrobial susceptibility profile. Am. J. Vet. Res.
        • SCANLAN, C.M., PURDY, C.W., and LOAN, R.W. 1992. Strain diversity of bovine Pasteurella haemolytica serovar 2 respiratory tract isolates. J. Vet. Diagn. Invest. in-press.
        • TIGGES, M.G., and LOAN, R.W. 1992. Serum antibody response to purified Pasteurella haemolytica capsular polysaccharide in cattle. Accepted. Am. J. Vet. Res. June.
        • PURDY, C.W., LOAN, R.W., and FOSTER, G.S. 1992. Pasteurella multocida strain variation in enzyme activity; isolates recovered from market stressed feeder calves. Conf. Res. Work. An. Dis. Chicago. Abst. No. 34.