Although poultry are considered a major reservoir for Campylobacter, ecology of this human pathogen in chicken flocks is poorly understood, hampering the design of effective intervention strategies. First, the prevalence, antigenic specificity, and bactericidal activity of poultry Campylobacter maternal antibodies (MAB) were investigated. High levels of specific antibodies were detected in egg yolks, sera of broiler breeders, and young broiler chicks, as maternally-derived. MAB was against multiple outer membrane components of Campylobacter, and active in antibody-dependent complement-mediated killing of C. jejuni. Second, the effect of Campylobacter MAB on the colonization of young chickens was investigated using challenge studies. Laboratory inoculation of commercial broilers showed that onset of colonization occurred much sooner in birds challenged at the age of 21-days (which were negative for Campylobacter antibody) than it did in birds inoculated at 3-days of age (which were positive for Campylobacter MAB). Challenge experiments using specific pathogen-free (SPF) chickens demonstrated that significant decreases in the percentage of colonized chickens were observed in 3-day old SPF chicks with Campylobacter MAB as compared with 3-day old chicks without Campylobacter-specific MAB. These results indicated that Campylobacter MAB plays a partial role in protecting young chickens against colonization. Lastly, we investigated the ability of Campylobacter to penetrate eggshells, and its prevalence and survival within eggs. Campylobacter was either unable to penetrate the eggshell or did not survive up to 48 h inside incubating eggs. C. jejuni survived for up to 14 days in eggs stored at 18 °C following injection into the egg yolk; however, viability was dramatically reduced in the albumen or the air sac. Although Campylobacter was detected in fresh eggs obtained from an SPF flock colonized by C. jejuni, storage of eggs for 7 days at 18 °C resulted in the lack of detection. No Campylobacter was detected from 500 eggs laid by Campylobacter -colonized commercial breeders, and 1,000 eggs from a commercial hatchery, suggesting that vertical transmission of Campylobacter through the egg is unlikely.
|School:||The Ohio State University|
|Department:||Veterinary Preventive Medicine|
|School Location:||United States -- Ohio|
|Source:||DAI-B 79/09(E), Dissertation Abstracts International|
|Keywords:||Campylobacter, Chickens, Colonization, Maternal antibodies, Transmission|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be