The haemagglutination spectrum of psittacine beak and feather disease virus

Area of Science:

• Veterinary Virology
• Avian Pathology
• Molecular Biology

Background:

• Psittacine beak and feather disease virus (PBFDV) causes significant mortality in psittacine birds.
• Accurate detection and characterization of PBFDV are crucial for disease management.
• Existing methods for virus concentration can be complex or inefficient.

Purpose of the Study:

• To develop a simple and effective method for concentrating PBFDV from feather samples.
• To characterize the properties of concentrated PBFDV, including its haemagglutination activity.
• To assess the distribution of PBFDV in tissues of affected birds.

Main Methods:

• Crude feather suspensions were treated with polyethylene glycol (PEG) for virus precipitation.
• Low-speed centrifugation was used to pellet the precipitated PBFDV.
• Isopycnic ultracentrifugation in caesium chloride (CsCl) gradients was employed for purification.
• Haemagglutination (HA) assays were performed using erythrocytes from various avian and mammalian species.

Main Results:

• PEG addition facilitated PBFDV precipitation and pelleting.
• Peak PBFDV HA activity was observed at a CsCl density of 1.35 g/ml.
• Purified PBFDV specifically agglutinated erythrocytes from several psittacine species.
• HA activity was stable over a range of temperatures, pH, and after chloroform treatment, but was lost at higher temperatures.

Conclusions:

• The described method provides a simple and efficient way to concentrate PBFDV.
• The HA assay using specific psittacine erythrocytes can be a valuable tool for PBFDV detection.
• High HA titres in feathers, serum, liver, and kidneys indicate widespread viral presence in affected birds.