|Event Title||First Global Alliance for Research on Avian Diseases (GARAD) Conference|
|Event Date & Time||On Mon, 29 Jun 2015 at 16:30:00 - 16:55:00|
|Venue||Edmond J. Safra Lecture Theatre|
|Abstract Title||Commensal or pathogen: pathogenicity traits of selected endemic microorganisms resolved in vivo|
|Affiliations||Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health And Christian Doppler Laboratory for Innovative Poultry Vaccines (IPOV) University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.|
Numerous microorganisms are endemic in a certain area and/or poultry species and the pathogencity is less well elucidated. In the actual presentation the pathogenicity of 3 different endemic microorganisms in chickens will be targeted, a parasite (Histomonas meleagridis), a bacterium (Gallibacterium anatis) and fowl adenoviruses (FAdV). Histomonas meleagridis is a flagellated protozoan parasite inducing histomonosis. In turkeys the disease is characterized by varying mortality which might reach up to 100%. In chickens the infection seems to be less severe, but outbreaks with increasing mortality and production losses are also reported. Existing experimental studies were mainly performed in pullets, although a drop in egg production is the leading sign noticed in the field. In a recent study we investigated the pathogenicity of a well defined culture in commercial layers. Although the parasites were mainly confined to the caeca a severe drop in egg production of about 30% was noticed which was much less severe in vaccinated birds. In agreement with this caecal lesions and atrophy of the reproductive tract were the main pathomorphological findings.The genus Gallibacterium was recently established within the family Pasteurellaceae Pohl 1981. It summarizes avian bacteria formerly known as Pasteurella haemolytica, Actinobacillus salpingitidis or Pasteurella anatis. Members of the genus Gallibacterium have been isolated from birds showing various clinical conditions. In fact, Gallibacterium spp. could be isolated from healthy birds and it has been suggested that these bacteria may be part of the normal flora in the upper respiratory and the lower genital tracts. Furthermore, there are also reports that Gallibacterium spp. have been isolated from layers with lesions affecting the reproductive tract with the consequence of salpingitis and severe drops in egg production. Until now, no studies were available investigating the pathogenicty of G. anatis in adult chickens, applying a natural infection route. In two separate experimental studies in layers and cockerels we were able to demonstrate the pathogenicity of G. anatis in mature birds, with consequences on egg production and semen quality. Presence of bacteria in eggs and semen underlines the importance of vertical transmission.