title: Genetic relationship of lyme disease spirochetes to Borrelia, Treponema, and Leptospira spp.
abstract: Genetic studies were performed on the following spirochetes: three Lyme disease spirochetes isolated from Ixodes ticks and from human spinal fluid; three species of North American borreliae; four species of Treponema; and two species of Leptospira. The mol% G+C values for Lyme disease spirochetes were 27.3 to 30.5%, similar to values of 28.0 to 30.5% for Borrelia species but different from the values of Leptospira or Treponema species which ranged from 35.3 to 53%. Lyme disease spirochetes represent a new species of Borrelia, with DNA homologies of 31 to 59% with the three North American strains of Borrelia studied. These studies also showed that Lyme disease spirochetes from three sources constituted a single species, with DNA homologies ranging from 76 to 100%. A high degree of relatedness was also seen between the three North American borreliae, with homology varying from 77 to 95%, indicating that these spirochetes represent a single species. Lyme disease spirochetes and Borrelia species exhibited almost no homology with Leptospira and Treponema species (0 to 2%). Plasmids were detected in the three Lyme disease spirochetes and in the three North American borreliae.
mesh_terms: D000818:Animals; D001482:Base Composition; D001898:Borrelia / Q000145:classification / Q000235:genetics*; D002555:Cerebrospinal Fluid / Q000382:microbiology; D003596:Cytosine / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis; D006147:Guanine / Q000032:analysis; D006801:Humans; D007919:Leptospira / Q000145:classification / Q000235:genetics*; D008193:Lyme Disease / Q000382:microbiology*; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D013143:Spirochaetaceae / Q000145:classification / Q000235:genetics*; D013987:Ticks / Q000382:microbiology; D014208:Treponema / Q000145:classification / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D006147:Guanine; D003596:Cytosine