Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCB110

Poster Communications

Bordetella pseudohinzii targets cilia and impairs tracheal cilia-driven transport in naturally-acquired infection in mice

A. Perniss1, N. Schmidt2, C. Gurtner3, K. Dietert3, M. weigel4, O. Schwengers4,5, J. Hempe6, C. Ewers2, U. Gaertner1, U. Pfeil1, A. D. Gruber3, T. Hain4,7, W. kummer1

1. Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany. 2. Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University, Giessen, United Kingdom. 3. Institute of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany. 4. Institute for Medical Microbiology, Justus Liebig University, Giessen, Germany. 5. Bioinformatics and System Biology, Justus Liebig University, Giessen, Germany. 6. Central Experimental Animal Facility, Justus Liebig University, Giessen, Germany. 7. German Center for Infection Research (DZIF), Partner Site Giessen-Marburg-Langen, Justus Liebig University, Giessen, Germany.

Objective: Characterization of the pathogenic potential of the newly described Bordetella strain, Bordetella pseudohinzii, which colonizes the respiratory tract of laboratory mice. Methods: Bacterial genome was analyzed using Illuminas NextSeq 500 next generation sequencing system. Tracheal particle transport speed (PTS) and ciliary beat frequency (CBF) were analyzed in explanted tracheas with a high speed camera and by tracking dynabeads. Histopathological changes of the airways were analyzed by H&E staining. Cultured tracheal rings were infected with isolated Bordetella pseudohinzii for 4 or 24 h and attachment of bacteria was visualized by electron microscopy (SEM and TEM); CBF and PTS were recorded after 4 h of infection. Results: Four bacterial isolates from lung and trachea of SPF-kept mice were identified as Bordetella pseudohinzii by genomic sequencing, presenting as rod-shaped coccobacilli with peritrichous flagellae in electron microscopy. Naturally-acquired infection with B. pseudohinzii lead to decreased number of tracheal ciliated cells (42.42 %, n=8, uninfected to 30.61.7 % infected, n=5; meanSEM), reduced CBF (18.21 0.60 to 12.121.48 Hz, n=7) and PTS (baseline: 60.72.76, n=19, to 24.512.79 µm/s, n=11). B. pseudohinzii-positive animals showed no clinical signs of infection, but neutrophils in BAL were highly increased (0.240.04 to 14.394.6 %; n=6). Histopathological analysis revealed tracheitis, interstitial pneumonia, and formation of tertiary lymphoid follicles (bronchus-associated lymphoid tissue = BALT) along the main and secondary bronchi. In in vitro-infected tracheal rings, B. pseudhohinzii attached to ciliated cells, formed biofilms and damaged the epithelium. PTS and CBF were significantly reduced after incubation for 4 h with 1.6x105 CFU. Conclusion: Colonization of mice with B. pseudohinzii leads to BAL neutrophilia, inflammation of the respiratory tract and impaired mucociliary clearance due to reduction and damage of ciliated cells. B. pseudohinzii may represent a novel mouse specific model organism to study closely related human lung pathogens like Bordetella hinzii and pertussis.

Where applicable, experiments conform with Society ethical requirements