The response of turkey poults to experimental infection with strains of M. gallisepticum of different virulence and with M. gallinarum.
In turkey poults aged up to 28 days, a virulent S6 strain of M. gallisepticum was recovered more frequently from more tissues for a longer time than were other strains. The virulent strain caused nervous signs and gross brain lesions in poults, and was often isolated from the brain, suggesting its neurotropism. All M. Gallisepticum strains were isolated from the synovial fluid of hocks, but swollen hocks and foot pads were seen only in poults infected with the A514 strain. It would seem, therefore, that although proclivity for joints was shown by all strains, only A514 produced grossly pathogenic effects in these young birds. All strains of M. gallisepticum showed some proclivity for respiratory tissues. Signs, gross lesions and recoveries of mycoplasma frequently failed to correlate. Perosis was seen in only two poults; these were infected with M. gallinarum with which the condition may, or may not, be associated. Serological reactions to both the rapid serum agglutination and haemagglutination inhibition tests developed in the 3rd and 4th weeks of life in all poults infected with M. gallisepticum strains although false positives and negatives were recorded. The main results of infection with the strains in turkey poults and in a similar study in chicks are summarised.
Varley
J
J
Sub-Department of Avian Medicine, University of Liverpool Veterinary Field Station, Neston, Wirral, England.
Jordan
F T
FT