Borrelia burgdorferi erp (ospE-related) gene sequences remain stable during mammalian infection.

A number of studies have indicated that Borrelia burgdorferi erp genes need not vary during vertebrate infection. However, it was recently reported that a B. burgdorferi bacterium reisolated from an infected mouse evidenced mutation and recombination events in several erp genes. Reexamination of that reisolate indicates that the previously reported changes were no doubt artifacts of the PCR processes originally used to clone those DNAs. Thus, no evidence has been found of erp gene variation during mammalian infection.