Location: Virus and Prion ResearchTitle: The Bordetella Bps polysaccharide is required for biofilm formation and persistence in the lower respiratory tract of swine
|SUKUMAR, NEELIMA - Wake Forest University|
|HORSWILL, ALEXANDER - University Of Iowa|
|DEORA, RAJENDAR - Wake Forest University|
Submitted to: Infection and Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2017
Publication Date: 5/30/2017
Citation: Nicholson, T.L., Brockmeier, S.L., Sukumar, N., Paharik, A.E., Lister, J.L., Horswill, A.R., Kehrli, M.E. Jr., Loving, C.L., Shore, S.M., Deora, R. 2017. The Bordetella Bps polysaccharide is required for biofilm formation and enhances survival in the lower respiratory tract of swine. Infection and Immunity. 00261-17. doi:10.1128/IAI.00261-17.
Interpretive Summary: Bordetella bronchiseptica is a bacterial respiratory swine pathogen that routinely infects pigs for long periods of time. This holds true despite the use of vaccines, where B. bronchiseptica is frequently isolated from the nose of vaccinated animals. Like many bacteria, B. bronchiseptica can form biofilms in the nose of animals, which protects the bacteria from a variety of clearance mechanisms and antimicrobial compounds. This study tested a known biofilm factor produced by bacteria termed Bps for its role in biofilm formation of swine isolates of B. bronchiseptica and its role in swine respiratory disease. We found that Bps was required for biofilm formation and for infecting the lungs or lower respiratory tract of swine. These findings provide critical information needed to design improved vaccines and intervention strategies to control or eliminate chronic carriage of B. bronchiseptica and other bacterial pathogens in swine.
Technical Abstract: Bordetella bronchiseptica is pervasive in swine populations and plays multiple roles in respiratory disease. Additionally, B. bronchiseptica is capable of establishing long-term or chronic infections in swine. Bacterial biofilms are increasingly recognized as important contributors to chronic bacterial infections. Recently the polysaccharide locus bpsABCD has been demonstrated to serve a critical role in the development of mature biofilms formed by the sequenced laboratory strain of B. bronchiseptica. We hypothesized that swine isolates would also have the ability to form mature biofilms and the bpsABCD locus would serve a key role in this process. A mutant containing an in-frame deletion of the bpsABCD structural genes was constructed in a wild-type swine isolate and found to be negative for PNAG-like material by immunoblot assay. Further, the bpsABCD locus was found to be required for the development and maintenance of the three-dimensional structures under continuous-flow conditions. To investigate the contribution of the bpsABCD locus to pathogenesis of B. bronchiseptica in swine, the KM22deltabps mutant was compared to the wild-type swine isolate for the ability to colonize and cause disease in pigs. The bpsABCD locus was found to not be required for persistence in the upper respiratory tract of swine. Additionally, the bpsABCD locus did not affect the development of anti-Bordetella humoral immunity, did not contribute to disease severity, and did not mediate protection from complement-mediated killing. However, the bpsABCD locus was found to be required for persistence in the lower respiratory tract of swine.