Plasmid DNA of virulent Alcaligenes faecalis.

Alcaligenes faecalis strains originating from chickens and from epizootics of coryza in turkeys were screened for antibiotic susceptibility and for the presence of plasmid DNA. Seven of 35 strains contained plasmid DNA ranging in size from 10.5 to approximately 32 megadaltons. All of the strains isolated from turkeys were virulent in turkey poults, but only the plasmid-containing strains were resistant to sulfonamides and streptomycin. Four of the plasmid-containing strains were also resistant to tetracycline. Five different plasmids representing at least 2 different incompatibility groups were identified in the 7 plasmid-bearing A faecalis strain.