Characterisation of Pasteurella multocida isolated from fowl cholera outbreaks on turkey farms

Abstract

P. multocida isolates from outbreaks of fowl cholera on 7 turkey farms in New South Wales were investigated using biochemical profiles, restriction endonuclease analysis (REA) and ribotyping. The available field evidence suggested that 8 cholera outbreaks had occurred with one farm suffering 2 outbreaks. 22 isolates obtained were all confirmed as P. multocida and allocated to 4 groups by biochemical profiles, 3 being variants of P. multocida subsp. multocida and the 4th being P. multocida subsp. septica . REA performed with Hpa II and ribotyping using Hpa II digests probed with the 16S rRNA operon of Haemophilus paragallinarum both established 7 groups.
Unlike the biochemical profiles, both REA and ribotyping provided a fine subdivision that identified outbreaks as either related or unrelated. The REA and ribotyping patterns as well as biochemical profiles were stable for all isolates from the outbreaks in which multiple isolates were obtained from either the same bird or from different birds. REA and ribotyping were superior to biotyping methods for the investigation of fowl cholera outbreaks.