Detection of proteolytic bacteria in the upper respiratory tract flora of poultry

Abstract

Proteolytic bacteria were readily demonstrated among the upper respiratory tract flora of poultry in two chicken flocks and two turkey flocks. Between 20% and 50% of birds in each flock had highly proteolytic bacteria in the upper respiratory tract flora, and the amount of the bacterial flora determined to be highly proteolytic in any given bird ranged from none to a majority. Highly proteolytic bacteria recovered included five species of staphylococci, as well as two gram-negative bacterial species, Flavobacterium sp. and Vibrio alginolyticus. All species of staphylococci isolated have previously been recovered from animal sources, whereas Flavobacterium sp. and V. alginolyticus are usually reported to be associated with soil and surface-water origins. The protocols used to screen for proteolytic bacteria among the flora and to assess protease activity required minimal supplies and equipment.