LEBENDES VACCIN GEGEN PASTEURELLA MULTOCIDA

摘要

The present invention relates to a live vaccine against Pasteurella multocida, for application of poultry by injection, per os or as aerosol, containing an attenuated non-virulent genetically stable strain of Pasteurella multocida, to a process for producing an attenuated genetically stable non-virulent strain of Pasteurella multocida, which comprises cultivating a virulent field strain, selecting after 18 hours at 37.degree.C colonies of uniform size, of about 4 to 5 mm diameter, suspending these in a pH 5.5 buffer, subjecting same to a mutagen at a concentration causing a mortality of 90-99 % after 30 minutes at 37.degree.C, centrifuging the microorganisms, washing sane, plating same and selecting colonies of not more than 2.5 to 3 mm diameter after 18 hours at 37.degree.C, purifying by reisolation of single colonies, testing for antigenic specificity and virulence, and selecting avirulent genetically stable immunologically effective mutants fur use in vaccines, and to a process for the vaccination of poultry which comprises applying such a vaccine by injection, per os or as aerosol.