Isolation, Identification, and Characterization of a New Highly Pathogenic Field Isolate ofspp..

Abstract

Avian tuberculosis is a chronic, contagious zoonotic disease affecting birds, mammals, and humans. The disease is most often caused byspp.(). Strain resources are important for research on avian tuberculosis and vaccine development. However, there has been little reported about the newly identifiedstrain in recent years in China. In this study, a new strain was isolated from a fowl with symptoms of avian tuberculosis by bacterial culture. The isolated strain was identified to beby culture, staining, and biochemical and genetic analysis, except for different colony morphology. The isolated strain was Ziehl-Zeelsen staining positive, resistant to p-nitrobenzoic acid, and negative for niacin production, Tween-80 hydrolysis, heat stable catalase and nitrate production. The strain had the DnaJ gene, IS, and IS, as well. Serum agglutination indicated that thestrain was of serotype 1. Thestrain showed strong virulencemortality in rabbits and chickens. The prepared tuberculin of thestrain had similar potency compared to thereference strain and standard tuberculina tuberculin skin test. Our studies suggested that thisstrain tends to be a novel subtype, which might enrich the strain resource of avian tuberculosis.