Characterisation of porcine haemophili isolated from Australian pigs between 1988 and 1992.

A total of 362 haemophili, isolated pigs throughout Australia, were characterised by phenotypic properties. Most were identified as Actinobacillus pleuro-pneumoniae (296 isolates) or Haemophilus parasuis (52 isolates). The remaining isolates were identified as Haemophilus Taxon 'minor group' (12 isolates) and Haemophilus Taxon D (two isolates). All 296 A pleuropneumoniae isolates were serotyped by slide agglutination and/or gel diffusion, using rabbit antisera against all 12 recognised serovars. Of these, only 156 (52.7%) could be assigned to a single serovar as follows: serovar 1-85 isolates, serovar 2-4 isolates, serovar 3-2 isolates, serovar 5-10 isolates, serovar 7-51 isolates, serovar 11-2 isolates and serovar 12-2 isolates. Of the remaining 140 isolates, 91 gave cross-reactions with serovars 3 and 6, one cross-reacted with serovars 9 and 10, one cross-reacted with serovars 9 and 11 whereas 47 gave no reaction with any of the antisera.