using , in southern blot analysis , a dna probe from the type 1 fimbrial switch , that hybridized to one dna band from phase-on bacteria and to two dna bands from phase-off bacteria , we found that the three clinical isolates expressing type 1 fimbriae contained the same invertible switch previously seen in the k-12 isolate .
C0000702
a dna
C0012854
dna