Molecular epidemiology of Ornithobacterium rhinotracheale.

Ornithobacterium rhinotracheale is a recently described gram-negative rod-shaped bacterium associated with respiratory tract infections in poultry. In order to determine the molecular epidemiology of this bacterium, we characterized 55 O. rhinotracheale isolates from eight countries on four continents by multilocus enzyme electrophoresis (MLEE), repetitive sequence based-PCR (rep-PCR), and 16S rRNA gene sequencing. MLEE discriminated the O. rhinotracheale isolates into six electrophoretic types (ETs), of which only three ETs were recovered from domesticated poultry. The 16S rRNA gene sequence and rep-PCR analyses confirmed the results obtained by MLEE and indicated limited heterogeneity among isolates of O. rhinotracheale recovered from poultry. Taken together, the results of our analysis demonstrate that the majority of O. rhinotracheale isolates recovered from domesticated poultry throughout the world are represented by a small group of closely related clones and suggest that the bacterium was recently introduced to domesticated poultry from wild bird populations.