Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/21/2006
Publication Date: 10/1/2006
Citation: Scupham, A.J. 2006. Intestinal flora of wild and domestic turkeys. In: Proceeding of the Food Safety Consortium. October 1-3, 2006, Fayetteville, Arkansas. 2006 CDROM.
Interpretive Summary: Currently 90% of turkeys are positive at slaughter for carriage of the food borne pathogen Campylobacter. An understanding of the ecology of this pathogen is essential for development of intervention strategies to exclude it from poultry and poultry products. The pathogen Campylobacter jejuni is the most common cause of bacterial-derived food borne illness in the United States, resulting in an estimated 2 million cases annually. Campylobacter is a commensal in the avian intestine and is commonly found in wild birds. However, the prevalence is less than that of commercial birds. We believe the high prevalence in commercial birds is a result of antibiotic use for both growth promotants and disease management resulting in unbalanced communities that are susceptible to invasion by Campylobacter. Establishment of mature, stable communities early in the life of the animal should competitively exclude Campylobacter from the intestinal environment. However, it is not currently known what constitutes a mature, stable intestinal community in poultry. Roughly 10**11 bacteria colonize the poultry ceca per gram of luminal contents, and the cultured bacterial component of commercially raised poultry has been estimated to be between 10% and 60%. Thus the composition of the intestinal microbiota of wild turkeys as compared to that of commercially raised turkeys was important to establish. We used a novel array-based method called Oligonucleotide Fingerprinting of rRNA Genes (OFRG) to describe the cecal microbiota from thirteen commercially raised and thirteen wild-caught turkeys. Commercial birds were sampled from two farms and samples were taken from wild birds killed during the 2004 Spring hunting season. A total of 2990 ribosomal clones were examined and classified, roughly 115 per animal. Ribosomal clone library composition was determined to include 49% Bacteroidetes (52% domestic, 48% wild), 30% Clostridiales (59% domestic, 41% wild), 3% Proteobacteria (87% domestic, %13 wild), 2% Deferribacteres (90% domestic, 10% wild) and 6% unidentified (32% domestic, 68% wild). While statistical measurements of diversity were similar, these results indicate that an overabundance of Proteobacteria and Deferribacteres were present in the commercial animals. These results can now be correlated to the Campylobacter loads identified in each animal and a hypothesis developed regarding the identities of bacteria that facilitate or inhibit Campylobacter colonization. These results provide baseline community composition information and will be important for researchers investigating various aspects of animal health, nutrition and food safety.
Technical Abstract: GOAL: To describe and compare the intestinal bacterial communities of domestic and wild turkeys. METHODS: Ceca from five domestic turkeys killed on-farm (Farm A) and eight from the abattoir (five from Farm A, three from Farm B) were examined for bacterial composition. Ceca from wild birds were procured during the 2004 Spring gun hunt season from Iowa (4 birds), Missouri (5 birds) and Wisconsin (4 birds). Bacterial 16S ribosomal genes were PCR amplified and cloned (2990 total clones). Clones were discriminated using Oligonucleotide Fingerprinting of rRNA Genes (OFRG). RESULTS: Bacterial library composition was determined to include 49% Bacteroidetes (52% domestic, 48% wild), 30% Clostridiales (59% domestic, 41% wild), 3% Proteobacteria (87% domestic, %13 wild), 2% Deferribacteres (90% domestic, 10% wild) and 6% unidentified (32% domestic, 68% wild). Within the Bacteroidetes, clones clustered indicating subsets specific to the wild and domestic birds as well as shared groups. One large group (86 clones or 6% of the Bacteroidetes clones) was specific to birds from Farm B. Of the Clostridiales, groups IV, IX and XIVa were predominant at 31%, 27% and 28%. Group IV clones showed similarity to the genera Faecalibacterium, Sporobacter and Anaerofilum, and most (74%) came from the commercial animals. Conversely, 83% of group IX clones with high sequence similarity to Megamonas hypermegale, Megasphaera elsdenii and Dialister derived from the wild birds. Clostridiales group XIVa clones derived primarily from commercial animals (64%). Most group XIVa clones were identifiable only to the class Clostridiales, but two clones were identified to the genus Dorea. Proteobacteria showed similarity to the genera Acinetobacter, Sutterella and Escherichia; Deferribacteres clones showed high similarity to Mucispirillum schaedleri. CONCLUSIONS: Wild and domestic turkeys host differing bacterial communities in their intestines. The contribution of host phenotype and lifestyle to the observed differences are currently unknown.