ARS | Publication request: Parsing the Allochthonous from the Autochthonous Fungal Biota in the Poultry Intestine

Submitted to: Meeting Abstract
Publication Type: Abstract
Publication Acceptance Date: April 7, 2008
Publication Date: N/A

Technical Abstract: Examination of intestinal microbial communities is complicated by the presence of both autochthonous (natively colonizing) and allochthonous (transient) taxa. To examine community dynamics in poultry ceca an experiment was performed in which day-old turkeys were housed in isolators on raised wire flooring. Half of the birds were orally inoculated with the intestinal contents of an adult turkey and half were sham inoculated. Turkeys had ad libitum access to irradiated feed and sterile water. Turkeys were killed at 21d and 18S libraries of their fungal communities, as well as the communities found in the adult inoculum and the irradiated feed, were examined via oligonucleotide fingerprinting of rRNA genes (OFRG). Within 1001 18S clones examined, a total of nine taxa were identified. Ascomycetes included two species of Candida, Eurotium herbariorum, a species with 96% sequence similarity to Kluyveromyces, and a species with 97% similarity to Cladosporium. Basidiomycetes included high- similarity (97%) and low- similarity (95%) groups related to Malassezia and both high- similarity (99%) and low- similarity (93-96%) groups related to Trichosporon. Candida edaphicus was prevalent in all four libraries, suggesting this yeast was present in the food. Trichosporon (99% similarity) represented 20% of the clones from sham inoculated birds, but less than 7% in the other libraries, suggesting this microbe colonized at hatch but was outcompeted by the adult inoculum. Malassezia (97% similarity) comprised 30% of the inoculated hatchling library, 14% of the adult inoculum library, and 4% of the sham inoculated hatchling library, indicating active colonization of the ceca by this fungus.