FIG. 8.

Polymorphism of CT135 in 15 reference laboratory strains. (A) CT135 PCR amplicons from 15 reference laboratory strains, representing the 15 major serovars, were digested with CEL I and run on an agarose gel. All strains except those of serovars K and L1, L2, and L3 exhibit digestion products indicating the presence of multiple genotypes of CT135 in these strains. (B) CEL I digestion of ompA from the same 15 strains. No digestion products were observed in any sample, indicating that all 15 strains contain only one genotype of ompA. A 1:1 mixture of serovars B and Ba was included as a positive control for CEL I digestion.