THE HEMAGGLUTINATION SPECTRUM OF PSITTACINE BEAK AND FEATHER DISEASE VIRUS

A simple method for concentrating psittacine beak and feather disease virus (PBFDV) from crude feather suspensions is described. The additio n of 10% polyethylene glycol (MW 6000 to 9000) to feather suspensions facilitated the precipitation and pelleting of PBFDV by low speed cent rifugation. Pellets were resuspended in one-twentieth of the original volume with caesium chloride (CsCl) buffer and subjected to isopycnic uitracentrifugation. Peak haemagglutination activity (HA) occurred at 1.35 g/ml in PBFDV CsCl gradients. CsCl purified virus agglutinated ga lah (Eolophus roseicapillus), eastern long-billed corella (Cacatua ten uirostris), sulphur-crested cockatoo (Cacatua galerita), Major Mitchel l's cockatoo (Cacatua lead-beaten and gang gang cockatoo (Callocephalo n fimbriatum) erythrocytes, but not those of 19 other avian or five ma mmalian species. PBFDV agglutinated galah erythrocytes at 4 degrees C and 37 degrees C over a wide range of pH and no change in HA titre was observed when PBFDV was treated with chloroform. HA persisted in PBFD V suspensions heated to 80 degrees C for 30 min, but was not detected after incubation at higher temperatures. High HA titres were detected in the feathers, serum, liver and kidneys of PBFD-affected birds.