CLINICAL MYCOPLASMA-GALLISEPTICUM INFECTION IN MULTIPLIER BREEDER ANDMEAT TURKEYS CAUSED BY F-STRAIN - IDENTIFICATION BY SODIUM DODECYL-SULFATE POLYACRYLAMIDE-GEL ELECTROPHORESIS, RESTRICTION-ENDONUCLEASE ANALYSIS, AND THE POLYMERASE CHAIN-REACTION

In February 1991, a flock of North Carolina multiplier breeder turkeys experienced respiratory signs, sinusitis, airsacculitis, and increase d mortality. Mycoplasma gallisepticum (MG) was isolated, and appropria te control measures were initiated. Ultimately, this outbreak involved several breeder flocks of an integrated turkey production company bef ore the last infected flock was identified in May 1991. During this ti me, MG was also isolated from a flock of commercial layer-type chicken s raised as pullets in close proximity to the index turkey flock. Sodi um dodecyl sulfate-polyacrylamide gel electrophoresis and restriction endonuclease analysis indicated that these isolates were identical to each other and to examples of the vaccinal F strain. Additionally, MG isolates from the affected turkey breeder and layer flocks were identi fied as MG F strain by use of an F strain-specific DNA probe and polym erase chain reaction. A separate outbreak of MG disease in several mea t-turkey flocks of a Midwest producer/processor yielded isolates ident ified as F strain by the polymerase chain reaction. These studies demo nstrated: 1) the utility of newer technologies for disease outbreak in vestigations; and 2) the potential of MG F strain to cause disease in breeder and meat turkeys under field conditions.