ORNITHOBACTERIUM RHINOTRACHEALE INFECTION IN BIRDS

Abstract

Ornithobacterium rhinotracheale is a recently discovered bacterium of the rRNA
superfamily V, first named in 1994. The first occurence was reported in wild birds and later shown to be widespread worldwide in commercial poultry. It has not been reported in Thailand. The bacterium causes important ecomonic losses in the poultry industry. O. rhinotracheale can affect almost all avian species and is associated with respiratory diseases. Airsacculitis and pneumonia are the most common features of infection. These clinical signs are aggravated by other factors, especially respiratory viruses and bacterial infections. Infection can be transmitted horizontally by aerosol droplets and also vertically in eggs. A PCR assay is a useful technique to aid epidemiological studies and is also suitable for identification purposes. Twelve serotypes can be differentiated within the species; serotype A being the most prevalent in poultry. The bacterium is always resistant to regular antibiotics. Autogenous inactivated vaccines has been successful in reducing clinical signs. Live vaccine is a feasible possibility but up to now, no avirulent strains of O. rhinotracheale have been found.