Biological Properties of a Chlamydia Strain Isolated from a Pet Bird, Budgerigar Which Was Kept by a Psittacosis Patient
A newly isolated Chlamydia, designated Izawa strain, was compared with the meningopneumonitis (MP) strain in morphology, serology and biophysical properties. The fine structure of the Izawa strain differed somewhat from the MP strain in the number of surface projections on the surface of elementary bodies (EBs), whereas no obvious difference was seen in the morphology of the chlamydia cells and intracytoplasmic inclusions. When EBs were centrifuged in linear gradients, the Izawa-EBs formed a band at a density of 1.19 g/ml, whereas the MP-EBs banded at a density of 1.21 g/ml. Reticulate bodies (RBs) of the Izawa strain were much more rigid to ultrasonic treatment which completely disintegrated the MP-RBs. There was no difference in the antigenicity between both strains when anti-Izawa rabbit or human serum was used, indicating the usefulness of the MP strain as antigen for the epidemiological survey and serodiagnosis of human sera.