Investigation of host receptors involved in Bordetella bronchiseptica infection
Bordetella bronchiseptica' infection in canines can result in tracheobronchitis (commonly known as kennel cough). An essential early step in 'B. bronchiseptica' infection is attachment of the bacterium to the cilia present on respiratory epithelial cells. I hypothesize that the receptors on host tissue utilized by 'B. bronchiseptica' are glycosphingolipids. Bacterial overlay experiments were conducted to identify species of glycolipid that bind 'B. bronchiseptica'. Solid-phase adherence assays were also performed using various pure glycolipids. The results suggest that lactosylceramide is a ligand for 'B. bronchiseptica' binding and that this binding requires the presence of both adhesins filamentous hemagglutinin (FHA) and fimbriae (FIM). GC-MS conducted on lipid preparations of canine cilia showed glucose, galactose, and 'N'-acetylglucosamine as the major sugar species present. Inhibition studies have shown that the lectin, wheat germ agglutinin, blocks binding of 'B. bronchiseptica ' to canine ciliated epithelial cells suggesting that 'N'-acetylglucosamine or sialic acid may be a component of the receptor.