ANALYSIS AND CHARACTERIZATION OF MYCOPLASMA-GALLISEPTICUM ISOLATES FROM PENNSYLVANIA

Because Mycoplasma gallisepticum F strain vaccine can be pathogenic in chickens and is pathogenic in turkeys, we monitored the spread of MG F strain into unvaccinated flocks by screening field and experimental isolates. Thirteen MG isolates obtained from various sources in Pennsy lvania were screened using several techniques capable of differentiati ng between MG strains. DNA restriction enzyme analysis (REA), Sodium d odecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) protein p rofiles, non-isotopic DNA probes, and a monoclonal antibody specific f or F strain were used to characterize each of the 13 isolates. Three o f the 13 isolates were identical to F strain; two of these were obtain ed from challenge studies, and one was a field isolate from a multiple -age commercial egg farm where the F strain vaccine had been used in t he past. The remaining 10 isolates were different from MG F strain but were quite similar if not identical to each other according to REA; S DS-PAGE protein profiles show similarities between the 10 isolates. Th e results suggested that F strain vaccine is not a major cause of fiel d outbreaks of MG in Pennsylvania.