Affiliation:
1. Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan
Abstract
The FlfA fimbrial protein is an important virulence factor and vaccine candidate of Avibacterium paragallinarum. Although all Taiwanese field strains of A. paragallinarumwere shown to contain an intact flfA gene, only some of them express the flfA protein in vitro. The aim of this study was to investigate how flfA expression is controlled in A. paragallinarum. The results of quantitative reverse transcription-polymerase chain reaction, 5[Formula: see text] rapid amplification of cDNA ends, and sequencing analyses showed that flfA expression is controlled by the length of a poly-cytidine (poly-C) tract that is located at the promoter region of flfA. In vitro passage of A. paragallinarum in chickens led to a change in the length of the poly-C tract and subsequently turned off flfA expression. These findings are valuable for understanding the mechanism of pathogenicity of A. paragallinarum.
Publisher
World Scientific Pub Co Pte Lt