Author
Scupham, Alexandra | |
Wesley, Irene | |
Thacker, Tyler |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 11/23/2007 Publication Date: 12/5/2007 Citation: Scupham, A.J., Wesley, I.V., Thacker, T.C. 2007. Campylobacter ecology in the turkey intestine: setting the stage for development of protective probiotics [abstract]. 42nd United States - Japan Cooperative Program in Natural Resources Panel of Animal and Avian Health Meeting. p.7. Interpretive Summary: Technical Abstract: Campylobacter species are the leading cause of bacterial food borne illness in the United States, causing two million cases of food-borne illness per year, as well as $1.5 to 1.8 billion in lost productivity. The primary source of infection is consumption of undercooked poultry, as prevalence of the pathogen approaches 90% on poultry carcasses. Thus, a dire need for intervention strategies exists. Previous studies of antibiotic-free turkeys indicated a possible link for Campylobacter colonization of the turkey cecum with an acute microbial community shift at 11 weeks of age. The current study examined Campylobacter ecology in the context of whole intestinal microbial community development in a commercial turkey flock, with five birds sampled every week for 18 weeks. These animals were exposed to growth promoting antibiotics, therapeutic antibiotics, coccidiostats and vaccinations against Newcastle’s disease and pneumovirus. Microbial community development was described using the molecular methods Automated Ribosomal Intergenic Spacer Analysis (ARISA) and terminal restriction-fragment length polymorphism (T-RFLP). Campylobacter species and subtypes were examined via multiplex PCR and amplified fragment length polymorphism (AFLP) analysis of experimental isolates. Results indicated that despite frequent antibiotic treatment, cecal microbial communities developed as previously identified, including early (weeks 1-5), transition (weeks 5-12) and late (weeks 12-18) stages. Two populations of transition communities were observed, one more similar to communities in the early stage and the other more similar to communities comprising the late stage. Each of the transition stages included a minor community shift at week 9. Succession of the dominant species included an increase in community complexity over time, with a predominance of Clostridiales and Lactobacillales in the early stage followed by a predominance of uncultured Firmicutes in the transition stage. The beginning of the late stage was marked by a bloom of Bacteroides species as described previously. Campylobacter jejuni was first identified at week 8, within the transition period but earlier than observed previously. Following its first appearance, C. jejuni isolates were identified rarely (5-10%) compared to the relatively nonpathogenic species C. coli. Only a single C. jejuni AFLP type was identified in this trial. Conversely, C. coli subpopulation succession was observed concurrent with the minor (week 9) and major (week 12) transitions. The results described here support the hypothesis that Campylobacter ecology is intimately tied to the ecology of the cecal microbiota as a whole. Development of intervention strategies for Campylobacter colonization of poultry will require examination of host/microbiota interactions, specifically identification of host signals involved in acute microbial community shifts as well as specific interactions between Campylobacter and competing members of the microbiota. |