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Effect of Infectious Bursal Disease on Campylobacter Infection in Chickens

Investigators
Saif, Linda; Jackwood, Daral
Institutions
Ohio State University
Start date
2002
End date
2007
Objective
  1. Elucidate the effect of experimental infections of chickens with IBDV on colonization, shedding and persistence of Campylobacter infections.
  2. Monitor commercial broiler flocks for possible effect of IBDV-specific maternal antibodies and vaccination for IBDV and incidence, shedding and persistence of Campylobacter infection.
More information
APPROACH: The colonization, shedding and persistence of Campylobacter infections will be measured and compared between groups of chickens with and without IBDV infections. Campylobacter will be detected using conventional culture methods and suspect colonies will be confirmed using a Campylobacter-specific PCR test designed from the cmp gene sequence of C. jejuni. IBDV will be identified using an RT/PCR test developed in our laboratory. The immunosuppressive effects of IBDV will be monitored using histology and bursa/body weight ratios. We will examine commercial broiler flocks for immunity to IBDV using the standard techniques of virus neutralization in cell culture and commercial ELISA.

PROGRESS: 2002/09 TO 2007/03 OUTPUTS: Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in humans in the US. Infectious bursal disease virus (IBDV) causes an immunosuppressive disease in young chickens. The goal of this project was to analyze a possible role of IBDV-induced immunosuppression in colonization and shedding of C. jejuni in chickens. The results of these studies demonstrated that IBDV infection exacerbated colonization and shedding of C. jejuni, presumably through the immune suppression this virus causes in chickens. These results were disseminated to poultry producers, veterinarians and poultry health professionals through publications and presentations made to the American Association of Avian Pathologists at the annual American Veterinary Medical Association meeting and at the XIII Congress of the World Veterinary Poultry Association. PARTICIPANTS: Individuals: Daral J. Jackwood, Principal Investigator Y. M. Saif, Co-Investigator Kathryn A. Subler, Graduate Student Claudia S. Mickael, Graduate Student Training or Professional Development: Kathryn A. Subler completed an M.S. degree Claudia S. Mickael completed a Ph.D. degree TARGET AUDIENCES: Results of the study were presented to members of the American Association of Avian Pathologists (AAAP). This group includes producers, veterinarians and scientists working in the areas of avian diseases and poultry production. Results of the study were also presented to the World Veterinary Poultry Association. Members of this international group include poultry producers, veterinarians and scientists. PROJECT MODIFICATIONS: The S3B strain of C. jejuni was isolated from poultry and was initially selected for these studies. It was determined that large doses of this strain were necessary to colonize chickens. Thus, the ATCC 33291 C. jejuni strain that was originally isolated from a human was used. IMPACT: 2002/09 TO 2007/03 Understanding the mechanism of C. jejuni infection in poultry is critical to eliminating the risk to public health. It is crucial to develop strategies for C. jejuni prevention and/or eradication at the farm level. Control of IBDV infections in chickens may be an advantageous step in the prevention/eradication process of foodborne bacteria such as Campylobacter spp and Salmonella spp. Devising an approach to reduce the threat of immunosuppressive agents may be necessary to control and prevent C. jejuni infection and shedding in poultry. In groups of chickens given only C. jejuni we isolated the bacterium from the cloaca and cecum, but not the small intestines. However, this bacterium was recovered from the small intestines, cecum and cloaca from all chickens in groups that were immune suppressed using IBDV prior to inoculation with C. jejuni. The amount (CFU/sample) of C. jejuni recovered from chickens in the immune suppressed chickens was significantly greater (p<0.05) than the amount recovered from chickens in groups that only received C. jejuni. Epidemiologic studies were conducted to determine if there is a link between IBDV induced immune suppression and C. jejuni in commercial broilers. Broiler farms were divided into those with IBDV as demonstrated by RT-PCR and those without the virus. Although C. jejuni was observed more frequently in broilers from IBDV infected farms, a significant correlation was not established. This may have been due to the poor quality of intestinal samples and the inherent difficulty of isolating C. jejuni from fresh/frozen tissue. It is also possible that some IBDV strains detected did not cause immune suppression because they were vaccine viruses or naturally attenuated strains. Nevertheless, the results of these studies demonstrated that IBDV infection exacerbated colonization and shedding of C. jejuni, presumably through the immune suppression this virus causes in chickens. It highlights the need for further investigation into the role of immunosuppression in preharvest control strategies for foodborne disease causing agents.

Funding Source
Nat'l. Inst. of Food and Agriculture
Project source
View this project
Project number
OHO00926-SS
Accession number
193750
Categories
Bacterial Pathogens
Campylobacter
Commodities
Meat, Poultry, Game