New On Nature.com: The Nasopharyngeal Microbiota Of Feedlot Cattle
Published online yesterday, October 26, 2015 by Scientific Reports, this paper by Devin B. Holman and Trevor W. Alexander (Lethbridge Research Centre, Agriculture and Agri-Food, Canada) and Edouard Timsitis, University of Calgary, Canada) is now available to view.
The bovine nasopharyngeal tract plays an important role in animal health and welfare by acting as a site for the carriage of pathogens causing bovine respiratory disease, a condition which results in significant morbidity and mortality in feedlot cattle. We characterized the bacterial nasopharyngeal microbiota in cattle at feedlot entry (day 0) and day 60 using 454 pyrosequencing. We also identified the most frequently isolated aerobic bacteria from nasopharyngeal swabs after plating onto three types of media. The cattle nasopharyngeal microbiota was composed primarily of Proteobacteria (68.9%) andFirmicutes (19.2%). At the genus-level, there was more inter-individual variability and a total of 55 genera were identified.
The genera Pseudomonas (23.7%), Shewanella (23.5%), Acinetobacter (17.5%), andCarnobacterium (12.2%) were most prevalent at entry, while after 60 days in the feedlot, Staphylococcus (20.8%), Mycoplasma (14.9%),Mannheimia (10.4%), and Moraxella (9.4%) were dominant. The nasopharyngeal microbiota also became more homogenous after 60 days in the feedlot and differed in structure at day 0 and 60. Using culture-based methods, the most frequently isolated bacteria from nasopharyngeal swabs were Bacillus, Staphylococcus, Moraxella,Pasteurella, and Mannheimia. These results provide insight into the nasopharyngeal microbiota of cattle and demonstrate that specific changes take place during feedlot production.