Source: UNIVERSITY OF ARIZONA submitted to
AN INTEGRATED APPROACH TO CONTROL OF BOVINE RESPIRATORY DISEASES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0210576
Grant No.
(N/A)
Project No.
ARZT-137030-R-02-134
Proposal No.
(N/A)
Multistate No.
NC-1027
Program Code
(N/A)
Project Start Date
Jul 1, 2007
Project End Date
Mar 20, 2009
Grant Year
(N/A)
Project Director
Billington, S. J.
Recipient Organization
UNIVERSITY OF ARIZONA
888 N EUCLID AVE
TUCSON,AZ 85719-4824
Performing Department
VETERINARY SCIENCE AND MICROBIOLOGY
Non Technical Summary
Bovine respiratory disease (BRD) continues to be the most costly disease problem facing the cattle industry. In cattle, respiratory disease occurs as a complex caused by a variety of bacteria and viruses, and is exacerbated by management practices. The BRD complex results in losses estimated as high as $3 billion annually to the US cattle industry. The opportunistic pathogen Arcanobacterium pyogenes is commonly isolated from upper respiratory disease in cattle, where it participates in polymicrobial infections. A. pyogenes is included in label claims for a tylosin injectable aimed at the treatment of BRD complex. Our studies will lead to an increased understanding of A. pyogenes pathogenesis with subsequent implications for diagnosis and intervention.
Animal Health Component
100%
Research Effort Categories
Basic
75%
Applied
25%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3113310110010%
3113410110010%
3113450110010%
3114010104040%
3114010110030%
Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3450 - Milk; 4010 - Bacteria; 3310 - Beef cattle, live animal; 3410 - Dairy cattle, live animal;

Field Of Science
1100 - Bacteriology; 1040 - Molecular biology;
Goals / Objectives
1. To evaluate the prevalence of viral and bacterial agents of respiratory disease by developing, validating and disseminating new state-of-the-art molecular diagnostics for rapid identification of these agents 2. To investigate the basic biology, molecular pathogenesis, and immunopathogenesis of polymicrobial infections including important viral and bacterial agents
Project Methods
The AZ station will contribute to two objectives of the NC 1027 multistate project; (1) to evaluate the prevalence of viral and bacterial agents of respiratory disease by developing, validating and disseminating new state-of-the-art molecular diagnostics for rapid identification of these agents, and (2) to investigate the basic biology, molecular pathogenesis, and immunopathogenesis of polymicrobial infections, including important viral and bacterial agents. Our research will be specifically aimed at the opportunistic pathogen Arcanobacterium pyogenes, a common participant in bovine respiratory disease complex and a target for intervention. Our specific aims are to (a) characterize the fimbrial adhesions of A. pyogenes, (b) examine the regulation of A. pyogenes virulence genes and (c) develop methods for the rapid detection of A. pyogenes strains involved in respiratory disease. We will use molecular approaches to target our specific aims. For specific aim 1, adherence factors such as neuraminidases and a collagen binding protein have previously been characterized. However, the latter at least, will only allow adherence to damaged tissue. The genome sequence of A. pyogenes contains four fimbrial operons whose expression may contribute to A. pyogenes adherence. We will use allelic exchange experiments to disrupt major subunit and accessory genes in these fimbrial operons and examine their affect on adherence to host epithelial cells. For specific aim 2, the regulation of virulence factors in A. pyogenes likely plays a significant role in its switch from a commensal to a pathogen. We have identified a two component regulatory system PloR/PloS which controls production of a major toxin, pyolysin and A. pyogenes proteases. Knockouts in ploS and ploR will be examined by RT-PCR for production of known and putative virulence factors such as pyolysin, proteases, DNase, neuraminidases, extracellular matrix binding proteins, and fimbriae using gene sequences obtained from the genome sequence. The effects of this two component system on virulence-associated characteristics such as host cell adhesion and invasion, uptake and survival in epithelial cells and biofilm formation will also be determined. For specific aim 3, we will develop antibodies and gene probes to A. pyogenes virulence factors known to be present in all A. pyogenes isolates, such as the neuraminidase NanH. We will then partner with diagnosticians to develop these reagents for rapid and high throughput diagnostic tests to detect A. pyogenes infections. These tests will include immunohistochemistry, in situ hybridization and/or lateral flow technology.

Progress 07/01/07 to 03/20/09

Outputs
OUTPUTS: Research at the AZ station is specifically aimed at the opportunistic pathogen Arcanobacterium pyogenes, a common participant in bovine respiratory disease complex and a target for intervention. Our specific aims are to (a) characterize the fimbrial adhesions of A. pyogenes, (b) examine the regulation of A. pyogenes virulence genes and (c) develop methods for the rapid detection of A. pyogenes strains involved in respiratory disease. We have determined a draft genome sequence of A. pyogenes strain BBR1 which has allowed the identification of four fimbrial operons whose expression may contribute to A. pyogenes adherence. Electron microscopy has tentatively identified fimbriae expressed on the surface of this organism. Gene knockouts have been constructed in the major subunit (fimA) and putative adhesin (fimB) genes of one of the operons and a decrease in adhesion to HeLa epithelial cells observed in the fimB mutant. A mutant in the putative response regulator PloR shows disparate effects on the expression of A. pyogenes virulence factors. The ploR mutant shows decreased production of the major toxin, PLO, but increased protease production. This duel regulation may be necessary to fine tune the production of virulence factors during complex infections such as BRD and other polymicrobial infections in which A. pyogenes participates. In addition, both fimbrial production and the PloR regulator effect the ability of A. pyogenes to form biofilms, likely an important factor in chronic disease. PARTICIPANTS: Stephen Billington, PI Helen Jost, Co-PI TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Bovine respiratory disease (BRD) continues to be the most costly disease problem facing the cattle industry. Arcanobacterium pyogenes is commonly isolated from upper respiratory disease in cattle, where it participates in polymicrobial infections. A. pyogenes is included in label claims for a tylosin injectable aimed at the treatment of BRD complex. An increased understanding of A. pyogenes pathogenesis will have subsequent implications for diagnosis and intervention.

Publications

  • No publications reported this period


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Research at the AZ station is specifically aimed at the opportunistic pathogen Arcanobacterium pyogenes, a common participant in bovine respiratory disease complex and a target for intervention. Our specific aims are to (a) characterize the fimbrial adhesions of A. pyogenes, (b) examine the regulation of A. pyogenes virulence genes and (c) develop methods for the rapid detection of A. pyogenes strains involved in respiratory disease. We have determined a draft genome sequence of A. pyogenes strain BBR1 which has allowed the identification of four fimbrial operons whose expression may contribute to A. pyogenes adherence. Electron microscopy has tentatively identified fimbriae expressed on the surface of this organism. Gene knockouts have been constructed in the major subunit (fimA) and putative adhesin (fimB) genes of one of the operons and a decrease in adhesion to HeLa epithelial cells observed in the fimB mutant. A mutant in the putative response regulator PloR shows disparate effects on the expression of A. pyogenes virulence factors. The ploR mutant shows decreased production of the major toxin, PLO, but increased protease production. This duel regulation may be necessary to fine tune the production of virulence factors during complex infections such as BRD and other polymicrobial infections in which A. pyogenes participates. In addition, both fimbrial production and the PloR regulator effect the ability of A. pyogenes to form biofilms, likely an important factor in chronic disease. PARTICIPANTS: Stephen Billington, PI Helen Jost, Co-PI TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Bovine respiratory disease (BRD) continues to be the most costly disease problem facing the cattle industry. Arcanobacterium pyogenes is commonly isolated from upper respiratory disease in cattle, where it participates in polymicrobial infections. A. pyogenes is included in label claims for a tylosin injectable aimed at the treatment of BRD complex. An increased understanding of A. pyogenes pathogenesis will have subsequent implications for diagnosis and intervention.

Publications

  • No publications reported this period


Progress 07/01/07 to 12/31/07

Outputs
OUTPUTS: Research at the AZ station is specifically aimed at the opportunistic pathogen Arcanobacterium pyogenes, a common participant in bovine respiratory disease complex and a target for intervention. Our specific aims are to (a) characterize the fimbrial adhesions of A. pyogenes, (b) examine the regulation of A. pyogenes virulence genes and (c) develop methods for the rapid detection of A. pyogenes strains involved in respiratory disease. We have determined a draft genome sequence of A. pyogenes strain BBR1 which has allowed the identification of four fimbrial operons whose expression may contribute to A. pyogenes adherence. Electron microscopy has tentatively identified fimbriae expressed on the surface of this organism. Gene knockouts have been constructed in the major subunit (fimA) and putative adhesin (fimB) genes of one of the operons and a decrease in adhesion to HeLa epithelial cells observed in the fimB mutant. A mutant in the putative response regulator PloR shows disparate effects on the expression of A. pyogenes virulence factors. The ploR mutant shows decreased production of the major toxin, PLO, but increased protease production. This duel regulation may be necessary to fine tune the production of virulence factors during complex infections such as BRD and other polymicrobial infections in which A. pyogenes participates. PARTICIPANTS: Stephen Billington (PI) Helen Jost (PI)

Impacts
Bovine respiratory disease (BRD) continues to be the most costly disease problem facing the cattle industry. Arcanobacterium pyogenes is commonly isolated from upper respiratory disease in cattle, where it participates in polymicrobial infections. A. pyogenes is included in label claims for a tylosin injectable aimed at the treatment of BRD complex. An increased understanding of A. pyogenes pathogenesis will have subsequent implications for diagnosis and intervention.

Publications

  • Rudnick, S.T., Jost, B.H., Baker, A.L. and Billington, S.J. (2008). Transcriptional regulation of pyolysin production in the animal pathogen, Arcanobacterium pyogenes. Vet. Microbiol. Manuscript Submitted.