Genotypic variation and mixtures of Lyme Borrelia in Ixodes ticks from North America and Europe.
BACKGROUND
Lyme disease, caused by various species of Borrelia, is transmitted by Ixodes ticks in North America and Europe. Studies have shown the genotype of Borrelia burgdorferi sensu stricto (s.s.) or the species of B. burgdorferi sensu lato (s.l.) affects the ability of the bacteria to cause local or disseminated infection in humans.


RESULTS
We used a multilocus PCR electrospray mass spectrometry assay to determine the species and genotype Borrelia from ticks collected in New York, Connecticut, Indiana, Southern Germany, and California and characterized isolates from parts of the United States and Europe. These analyses identified 53 distinct genotypes of B. burgdorferi sensu stricto with higher resolution than ospC typing. Genotypes of other members of the B. burgdorferi sensu lato complex were also identified and genotyped including B. afzelii, B. garinii, B. lusitaniae, B. spielmanii, and B. valaisiana. While each site in North America had genotypes unique to that location, we found genotypes shared between individual regions and two genotypes found across the United States. Significant B. burgdorferi s.s. genotypic diversity was observed between North America and Europe: only 6.6% of US genotypes (3 of 45) were found in Europe and 27% of the European genotypes (3 of 11) were observed in the US. Interestingly, 39% of adult Ixodes scapularis ticks from North America were infected with more than one genotype of B. burgdorferi s.s. and 22.2% of Ixodes ricinus ticks from Germany were infected with more than one genotype of B. burgdorferi s.l.


CONCLUSIONS
The presence of multiple Borrelia genotypes in ticks increases the probability that a person will be infected with more than one genotype of B. burgdorferi, potentially increasing the risks of disseminated Lyme disease. Our study indicates that the genotypic diversity of Borrelia in ticks in both North America and Europe is higher then previously reported and can have potential clinical consequences.
Crowder
Chris D
CD
Ibis Biosciences, Carlsbad, California, United States of America.
Matthews
Heather E
HE
Schutzer
Steven
S
Rounds
Megan A
MA
Luft
Benjamin J
BJ
Nolte
Oliver
O
Campbell
Scott R
SR
Phillipson
Curtis A
CA
Li
Feng
F
Sampath
Ranga
R
Ecker
David J
DJ
Eshoo
Mark W
MW
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001898:Borrelia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005060:Europe; D056426:Genetic Loci / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D006801:Humans; D018884:Ixodes / Q000382:microbiology*; D008193:Lyme Disease / Q000382:microbiology* / Q000469:parasitology*; D009656:North America; D016133:Polymerase Chain Reaction; D021241:Spectrometry, Mass, Electrospray Ionization
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; C079616:OspC protein