Open AccessInsights into Pasteurellaceae carriage dynamics in the nasal passages of healthy beef calves
Author(s) -
Amy Thomas,
Michael Bailey,
Michael R. F. Lee,
Andrew Mead,
Begonia Morales-Aza,
Rosy Reynolds,
Barry Vipond,
Adam Finn,
M. Eisler
Publication year - 2019
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-019-48007-5
Subject(s) - pasteurella multocida , carriage , pasteurellaceae , pasteurella , biology , microbiology and biotechnology , zoology , confidence interval , veterinary medicine , medicine , bacteria , haemophilus influenzae , antibiotics , pathology , genetics
We investigated three bovine respiratory pathobionts in healthy cattle using qPCR optimised and validated to quantify Histophilus somni , Mannheimia haemolytica and Pasteurella multocida over a wide dynamic range. A longitudinal study was conducted to investigate the carriage and density of these bacteria in the nasal passages of healthy beef calves (N = 60) housed over winter in an experimental farm setting. The three pathobiont species exhibited remarkably different carriage rates and density profiles. At housing, high carriage rates were observed for P . multocida (95%), and H . somni (75%), while fewer calves were positive for M . haemolytica (13%). Carriage rates for all three bacterial species declined over the 75-day study, but not all individuals became colonised despite sharing of environment and airspace. Colonisation patterns ranged from continuous to intermittent and were different among pathobiont species. Interval-censored exponential survival models estimated the median duration of H . somni and P . multocida carriage at 14.8 (CI 95% : 10.6–20.9) and 55.5 (CI 95% : 43.3–71.3) days respectively, and found higher density P . multocida carriage was associated with slower clearance (p = 0.036). This work offers insights into the dynamics of pathobiont carriage and provides a potential platform for further data collection and modelling studies.