Tracheal Mucus Transport Rate and Bacterial Clearance in Turkeys Exposed by Aerosol to La Sota Strain of Newcastle Disease Virus

Abstract

Tracheal mucus transport rate (TMTR) and quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sac were measured in healthy unanesthetized turkeys and in turkeys exposed by aerosol to a La Sota vaccine strain of Newcastle disease virus (NDV). The TMTR of uninfected turkeys was 42.4 +/- 14.7 cm/min. The TMTR of NDV-infected turkeys was depressed on days 3 through 7 postexposure (PE); depression was significant (P less than or equal to 0.05) on day 7 PE. Tracheal E. coli clearance in NDV-infected turkeys was reduced on days 4 through 9 PE, significantly so on day 5 PE (P less than or equal to 0.01). Depression of TMTR and tracheal E. coli clearance were associated histologically with replacement of normal pseudostratified columnar epithelium by 3 to 8 layers of immature nonciliated cells. E. coli clearance by the lung and air sac of NDV-infected turkeys was depressed on days 5 through 9 PE.