Atypical Pasteurella haemolytica type A from poultry.

Atypical strains of Pasteurella haemolytica that failed to ferment maltose were isolated from nodular necrosis in the liver and heart blood of domestic fowl (Gallus domestica). These strains did not typically behave like either of the two well-known biotypes of P. haemolytica. The strains utilized trehalose and produced hydrogen sulfide (H2S), thus behaving like P. haemolytica type T, and produced acid in xylose but not in salicin, thus behaving like P. haemolytica type A. Most of the properties of the strains, however, conformed closely to those of P. haemolytica type A. Detailed characteristics of the isolates are described and discussed.