Comparative Analyses of a Cystic Fibrosis Isolate of Bordetella bronchiseptica Reveal Differences in Important Pathogenic Phenotypes

Abstract

ABSTRACTBordetella bronchisepticais a Gram-negative bacterium that infects and causes disease in a wide variety of animals.B. bronchisepticaalso infects humans, thereby demonstrating zoonotic transmission. An extensive characterization of humanB. bronchisepticaisolates is needed to better understand the distinct genetic and phenotypic traits associated with these zoonotic transmission events. Using whole-genome transcriptome and CGH analysis, we report that aB. bronchisepticacystic fibrosis isolate, T44625, contains a distinct genomic content of virulence-associated genes and differentially expresses these genes compared to the sequenced model laboratory strain RB50, a rabbit isolate. The differential gene expression pattern correlated with unique phenotypes exhibited by T44625, which included lower motility, increased aggregation, hyperbiofilm formation, and an increasedin vitrocapacity to adhere to respiratory epithelial cells. Using a mouse intranasal infection model, we found that although defective in establishing high bacterial burdens early during the infection process, T44625 persisted efficiently in the mouse nose. By documenting the unique genomic and phenotypic attributes of T44625, this report provides a blueprint for understanding the successful zoonotic potential ofB. bronchisepticaand other zoonotic bacteria.