Purification and preliminary characterisation of a pathogenic strain of infectious bursal disease virus

Abstract

A pathogenic strain of infectious bursal disease virus has been purified by density gradient centrifugation, principally on sucrose and tartrate gradients. Examination of gradient peak fractions by electron microscopy has revealed two populations of particles of average size 62 nm and 20 nm, which band together on sucrose and tartrate gradients. Purified virus has been shown to reproduce the typical symptoms and lftsions of infectious bursal disease. The possible classification of the larger virus particle in the diplornavirus group and the origin of the smaller particle are discussed.

Close proximity risk assessment for SARS-CoV-2 infection

“…(3) , , d d ( m ) and Re d represent, respectively, the density, diameter and Reynolds number of the droplet. The droplet density has been considered constant and equal to 1200 kg m −3 as representative of the density of non-volatile components carried by respiratory droplets ( McCombs and Rawls, 1968 ; Pattison et al, 1975 ; Ritchie et al, 1973 ). The Re d is calculated as: where is the air density, whereas the drag coefficient, C D , in Eq.…”

Further morphological characterization and structural proteins of infectious bursal disease virus

“…A recent study has suggested that surface immunoglobulin M-bearing B lymphocytes are target cells for infection by the IBD virus (IBDV) (3). Electron microscopy has shown that IBDV is a nonenveloped icosahedron with diameters ranging from 55 to 65 nm (1,2,5,13). In a previous study (5), we suggested that the capsid of the virion consisted of 32 capsomeres, each composed of five or six structural units, and that IBDV resembled bluetongue virus in morphology.…”