Genetic heterogeneity of Borrelia burgdorferi in the United States

J Infect Dis. 1997 Jan;175(1):98-107. doi: 10.1093/infdis/175.1.98.


To examine in detail Borrelia burgdorferi strain diversity in the United States, 186 isolates from human, tick, and rodent sources were analyzed from multiple distinct geographic regions of the United States and abroad. Strains were characterized by genomic macrorestriction analysis and ospA and 23S rDNA gene sequencing followed by phylogenetic analysis. Results indicate that spirochetal isolates from the United States fall into two major divisions and nine or more subdivisions; human isolates fell into five of these subdivisions. Greater genetic diversity was observed among B. burgdorferi isolates from moderate climatic regions, consistent with increased tick vector and reservoir diversity. All of the Borrelia isolates were reactive by ospA polymerase chain reaction except for Borrelia hermsii controls and several tick isolates from the Northeast, which were shown to lack the 49-kb plasmid encoding outer surface protein A (OspA). The data suggest that US B. burgdorferi isolates demonstrate substantial genetic heterogeneity, with regional differences in spirochete populations.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Surface / genetics
  • Arachnid Vectors / microbiology*
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Vaccines
  • Borrelia burgdorferi Group / classification
  • Borrelia burgdorferi Group / genetics*
  • Borrelia burgdorferi Group / isolation & purification
  • Climate
  • DNA, Ribosomal / genetics
  • Disease Reservoirs
  • Electrophoresis, Gel, Pulsed-Field
  • Genes, Bacterial
  • Genetic Heterogeneity*
  • Genetic Variation
  • Humans
  • Ixodes / microbiology*
  • Lipoproteins*
  • Lyme Disease / microbiology*
  • Phylogeny
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • RNA, Bacterial / genetics
  • RNA, Ribosomal, 23S / genetics
  • Rodentia / microbiology*
  • United States


  • Antigens, Surface
  • Bacterial Outer Membrane Proteins
  • Bacterial Vaccines
  • DNA, Ribosomal
  • Lipoproteins
  • OspA protein
  • RNA, Bacterial
  • RNA, Ribosomal, 23S