CHARACTERIZATION OF LEPTOSPIRACEAE BY 16S-DNA RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS

Chromosomal DNA from 37 Leptospiracaea representing genetic species, groups and reference strains together with five leptospire isolates and Escherichia coli were digested with the restriction endonucleases BamHI, ClaI and EcoRI. The Southern blots were hybridized with a biotinylated E. coli 1.5 kb 16S rDNA probe and gave 36 reproducible and unique patterns. With the exception of the type strain (Leptospira interrogans serovar icterohaemorrhagiae RGA) and neotype strain (serovar icterohaemorrhagiae Ictero no. 1) all the species and taxa examined could be differentiated from each other on the basis of their BamHI, ClaI and EcoRI restriction fragment length polymorphisms (RFLP). L. interrogans and L. borgpetersenii reference strains were heterogeneous, whereas Leptonema illini and L. parva incertae sedis were distinct and separate. Strains representing L. biflexa sensu lato presented divergent RFLP patterns. A porcine isolate was identified to be L. interrogans pomona Pomona.