Ornithobacterium rhinotracheale is a rod-shaped, gram-negative, and mostly oxidase-positive bacterium that causes respiratory infections in chickens and turkeys worldwide and can also spread to nonrespiratory organs. The present report analyzes 294 cases in which O. rhinotracheale was isolated from turkeys or chickens in central California in the years 2000 through 2012. Two hundred sixteen cases were from turkey flocks and 78 from chicken flocks. The median age of turkey flocks was 8.7 wk; the median age of chicken flocks was 6.4 wk. From turkeys, O. rhinotracheale was more often isolated from August to January than during the rest of the year. Chickens cases were more evenly distributed throughout the year. The organs with the highest isolation rate were the infraorbital sinus and trachea, followed by lungs and air sacs. Isolation from other organs was rare. Pure cultures were obtained from relatively more turkey organs than chicken organs. The organ from which there was the highest chance to obtain a pure culture was the air sac. In 108 turkey flocks (50.0%) and 64 chicken flocks (82.1%) at least one other respiratory pathogen was detected. The most common gross lesions were increased mucus in trachea, caseous or fibrinous exudate in the air sacs, consolidated lungs indicating pneumonia, congested and edematous lungs, and a flattened trachea. For most types of lesions, the percentage of affected turkeys was higher than the percentage of affected chickens. The percentage of birds with lesions was higher if other respiratory pathogens were present. Overall, the host species (turkey or chicken) was a more important factor for the prevalence of most lesions than the detection of other respiratory pathogens. The most common histopathologic lesions in the sinus and trachea were heterophilic or mononuclear inflammatory cell infiltration. In the lungs and air sacs, the inflammation was characterized by heterophilic infiltration and/or fibrin accumulation. These results are helpful in selecting the most appropriate samples for isolation of O. rhinotracheale. In addition, they show the incidence of the bacterium in turkeys and chickens and which lesions can be expected after infection with O. rhinotracheale, and they indicate that in some cases O. rhinotracheale can be the primary, or at least the major, pathogen.

Estudio retrospectivo de aislamientos de Ornithobacterium rhinotracheale de pollos y de pavos en el centro de California: 294 casos (2000–12).

Ornithobacterium rhinotracheale es una bacteria bacilo Gram negativo y principalmente oxidasa positivo que causa infecciones respiratorias en pollos y en pavos en todo el mundo y también puede extenderse a órganos no respiratorios. El presente informe analiza 294 casos en los que O. rhinotracheale fue aislado de pavos o pollos en el centro de California entre los años 2000 al 2012. Doscientos dieciséis casos fueron de parvadas de pavos y 78 casos fueron procedentes de pollos. La edad media de las parvadas de pavos fue de 8.7 semanas; la edad media de los lotes de pollos fue de 6.4 semanas. En los pavos, O. rhinotracheale fue más frecuentemente aislado de agosto a enero en comparación con el resto del año. Los casos de pollos casos fueron distribuidos de manera más uniforme a lo largo del año. Los órganos con la tasa más alta de aislamiento fueron los senos infraorbitarios y la tráquea, seguida de pulmones y sacos aéreos. El aislamiento de otros órganos fue muy poco frecuente. Los cultivos puros se obtuvieron relativamente más frecuentemente de órganos de pavo en comparación que de los órganos de pollo. El órgano que mostró la posibilidad más alta de obtener cultivo puro fue de los sacos aéreos. En 108 parvadas de pavos (50.0%) y 64 parvadas de pollos (82.1%) se detectó al menos otro patógeno respiratorio. Las lesiones macroscópicas más comunes fueron