TAXONOMIC RELATIONSHIP OF VOLE AGENT TO ROCHALIMAEA-QUINTANA

The recent claim that the vole agent, a rickettsia-like microorganism isolated from wild voles by Baker in 1946, is actually a strain of R. quintana, the etiological agent of trench fever. The 2 organisms were compared on the basis of percent guanine-plus-cytosine content, genome size, DNA-DNA hybridization, polypeptide composition and serological relationships. Although the 2 organisms do have identical or nearly identical DNA base ratios and show some serological cross-reactions, they differ substantially by all of the other criteria employed. They are clearly different, although possibly related, organisms. It remains to be determined whether they can be regarded as 2 spp. of the same genus. An Old World strain and a New World strain of R. quintana were indistinguishable from one another by the same criteria.