title: Evolution of the nasopharyngeal microbiota of beef cattle from weaning to 40 days after arrival at a feedlot.
abstract: Bovine respiratory disease complex (BRDc) is a major cause of morbidity and mortality in beef cattle. There is recent evidence suggesting that the nasopharyngeal microbiota has a key role in respiratory health and disease susceptibility in cattle. However, there is a paucity of knowledge regarding evolution of the nasopharyngeal microbiota when cattle are most likely to develop BRDc (i.e., from weaning to 40days after arrival at a feedlot). The objective was to describe the evolution of the nasopharyngeal microbiota of beef cattle from weaning to 40days after arrival at a feedlot. Deep nasal swabs (DNS) from 30 Angus-cross steers were collected at weaning, on arrival at a feedlot, and at day 40 after arrival. The DNA was extracted from DNS and the hypervariable region V3 of the 16S rRNA gene was amplified and sequenced (Illumina MiSeq platform). Nasopharyngeal microbiota underwent a profound evolution from weaning to arrival at the feedlot and from arrival to day 40, with the abundance of 92 Operational Taxonomic Units (OTUs) significantly changing over time. Mycoplasma (M. dispar and M. bovirhinis) was the most abundant genus in the nasopharynx, accounting for 53% of the total bacterial population. Because an evolving bacterial community may be less capable of resisting colonization by pathogenic bacteria, the instability of the nasopharyngeal microbiota documented in this study might explain why cattle are most likely to be affected with BRDc during the first weeks after weaning and arrival at a feedlot.
authors.affiliation: Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada. Electronic address: eftimsit@ucalgary.ca.
authors.forename: Edouard
authors.initials: E
authors.lastname: Timsit
authors.affiliation: Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Workentine
authors.affiliation: Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada; Faculty of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Schryvers
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
authors.forename: Devin B
authors.initials: DB
authors.lastname: Holman
authors.affiliation: Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: van der Meer
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Alexander
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D044822:Biodiversity; D048090:Bovine Respiratory Disease Complex / Q000382:microbiology; D002417:Cattle; D004198:Disease Susceptibility / Q000382:microbiology; D008297:Male; D064307:Microbiota / Q000502:physiology*; D009174:Mycoplasma / Q000235:genetics / Q000302:isolation & purification; D009305:Nasopharynx / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014886:Weaning
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: 16S rRNA gene; Bovine respiratory disease; Metagenomics; Shipping fever