EXPERIMENTAL CHLAMYDIA-PSITTACI INFECTION OF JAPANESE-QUAIL

Japanese quail were used for the infection model of avian chlamydiosis . One-day-old Japanese quail were highly susceptible to lethal infecti on by a Chlamydia psittaci strain of budgerigar origin upon inoculatio n via the air sac route with 10(4.1) FFU of the organism, showing an a cute and lethal course with chlamydial propagation. In contrast, 7-day -old quail developed resistance to the infection as shown by the lack of lethal effect with the same dose. The resistance of 7-day-old birds was abolished by immunosuppressive treatment with cyclophosphamide. U pon inoculation with a sublethal dose of 10(2.1) FFU, latent infection was established in 1-day-old birds with a minimum number of the organ ism. The latent infection in the birds was converted to the lethal for m by treatment with cyclophosphamide along with chlamydial propagation and suppression of antibody production.