Adherence of Ornithobacterium rhinotracheale to chicken embryo lung cells as a pathogenic mechanism.

Ornithobacterium rhinotrachealeis a bacterium that causes respiratory disease in birds and it has been isolated in countries with a large poultry production, including Mexico. The pathogenicity mechanisms of this bacterium have not been completely elucidated yet. The capacity of the bacterium to adhere to epithelial cells of chickenin vitrohas been evidenced, and since this bacterium has been isolated from the lungs and air sacs of several avian species, the aim of this study was to determine if this bacterium can adhere to chicken lung cells. We used fiveO. rhinotrachealereference serovars (A–E) that were in contact with primary lung cells cultured from a 19-day-old chicken embryo.O. rhinotrachealeadherence was evaluated through optical and transmission electron microscopies. The results revealed thatO. rhinotrachealeis capable of adhering to chicken embryo lung cells within 3 h of incubation with a diffuse adherence pattern. The adherence percentages of the chicken embryo lung cells were 51–96% according to the serovar of the bacterium. Relative adherence was from 4 to 8 bacteria per cell. Transmission electron microscope data revealed intracellular bacteria inside a vacuole in less than 3 h of incubation. [ABSTRACT FROM AUTHOR]