Conjugal transfer of an R-plasmid in Pasteurella multocida.

A strain of Pasteurella multocida isolated from turkeys during an outbreak of septicemic disease (fowl cholera) was shown to possess the ability to transfer streptomycin and sulphadiazine resistance to P. multocida and to Escherichia coli by conjugation. The genes necessary for the transfer of the resistance genes appeared to be associated with a plasmid of molecular weight 28.5 x 10(6). The resistance genes were shown to be associated with a second plasmid of molecular weight 7.2 x 10(6).