Serological classification of recent infectious bronchitis virus isolates by the neutralization of immunofluorescent FOCI.

The neutralisation of immunofluorescent foci test was adapted to the grouping of 14 recent Dutch infectious bronchitis virus isolates. This test provides a distinct grouping of the isolates and the corresponding sera. Evaluation of the tests was carried out by means of the computer program called 'Taxonomic', designed for the calculation of taxonomic order from serological data. The taxonomic order, depicted in the form of a tree, facilitates the judgement of the degree of resemblance between viruses or groups of viruses as well as sera. Using this test the isolates of infectious bronchitis virus can be classified into distinct groups.