A whole-organ perfusion model of Bordetella pertussis adherence to mouse tracheal epithelium

A whole-organ perfusion system was used to culture tracheas from adult Swiss mice and test this system's adaptability for use in adherence assays for virulent Bordetella pertussis. Culture medium and bacterial suspensions flowed readily through the tracheal lumen, ciliary activity was maintained throughout the culture period, and scanning electron microscopy revealed retention of normal surface morphology. The number of adherent colony-forming units (cfu) per trachea was determined for all three Bordetella species every 30 min over a 3.5-h incubation period and the resultant adherence patterns were reproducible. Adherent cfu were dependent on the concentration of microorganisms in the infecting inoculum. Bordetella pertussis did not demonstrate a preferential adherence to either the dorsal or ventral surface of the tracheal epithelium nor did it demonstrate a preference for adherence to the laryngeal or bronchial end of the trachea. Static growth conditions did alter the adherence pattern of B. pertussis from that observed when the organism was grown with constant agitation.