Pasteurella haemolytica of cattle: serotype, production of beta-galactosidase and antibacterial sensitivity.

Two hundred and three isolates of Pasteurella haemolytica from cattle were studied. They originated from the nasal cavity of cattle in housed herds; the nasal cavity and pneumonic lungs of experimental feedlot calves and from pneumonic bovine lungs submitted for bacteriological diagnosis.To determine whether a single characteristic or combination of characteristics might be a feature of isolates collected from animals with pneumonic pasteurellosis (Shipping Fever), the following tests were made. Cultures were serotyped by indirect haemagglutination; the ability to produce beta-galactosidase was examined in the ortho-nitrophenyl-beta-D-galactopyranoside (ONPG) test and antibacterial sensitivity tests were done. None of these factors could be directly related to the role of P. haemolytica in "Shipping Fever".