Avoidance of non-specific agglutination of Mycoplasma gallisepticum by the use of a globulin-free antigen

Isolation and identification of avian mycoplasmas in Singapore

Two hundred and forty batches of chickens with chronic respiratory syndrome were tested for mycoplasmas. One hundred and five batches (43.8%) were found to have mycoplasmosis. A total of 110 isolates of mycoplasma was cultured, of which nine isolates were identified as Mycoplasma gallisepticum, 48 avian sero-group D, 45 M. gallinarum, one M. iners and seven unclassified. 2. Identification of the mycoplasmas isolated was carried out by biochemical and serological tests (disc growth inhibition and agar gel diffusion tests). A modified agar gel diffusion test using solubilised antigens with sodium deoxycholate-glucose solution was developed for serotying of mycoplasmas.

A comparison of three Mycoplasma synoviae rapid plate agglutination antigens in experimental M. synoviae infection in chickens

The course of experimental Mycoplasma synoviae and Mycoplasma galli-septicum infections was followed in groups of chickens to compare the specificity and sensitivity of three, commercially available, Mycoplasma synoviae rapid plate antigens and to determine the development of rheumatoid factor-like antiglobulins in their serum. All three antigens were adequate in sensitivity but one of them, which was found to contain 7% serum albumen, had better specificity in that it was not agglutinated by chicken antiglobulins prepared against either pig globulin or culture medium. Examination of the non-specific reactivity of M. synoviae antigen preparations containing different concentrations of pig globulin or 7% bovine albumen showed that the presence of 7% albumen or globulin suppressed the speed of non-specific reactions. Antiglobulin activity using globulin-coated latex was detected in the serum of chickens up to 62 weeks after foot pad inoculation with M. synoviae ; specific antibody, on the other hand, was still present when the experiment was terminated at 107 weeks post-inoculation. A serologically-positive M. synoviae infection in chickens produced by contact with birds infected via the respiratory tract did not stimulate antiglobulins detectable by the Latex test.