Identification of ‘Haemophilus somnus’ by rapid tests for pre‐formed enzymes

In rapid tests for pre‐formed enzymes, all strains of ‘Haemophilus somnus’ examined gave positive reactions for alkaline phosphatase, cytochrome oxidase, β‐glucosidase, β‐glucuronidase and hippurate hydrolase but were negative for α‐mannosidase, β‐galactosidase and β‐xylosidase, tributyrin esterase, cystine aminopeptidase and γ‐glutamyl aminopeptidase. The pattern of results differed from those given by Actinobacillus, Haemophilus, ‘Histophilus’, Pasteurella and Taylorella species.