Detection of Borrelia burgdorferi Sensu Stricto ospC Alleles Associated with Human Lyme Borreliosis Worldwide in Non-Human-Biting Tick Ixodes affinis and Rodent Hosts in Southeastern United States

Comparative analysis ofospC genes from 127Borrelia burgdorferi sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations.ospC alleles A, B, and L were detected on both continents in vectors and hosts, including humans. SixospC alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. TenospC alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. FourospC alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis ofospC alleles ofB. burgdorferi strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate thatospC genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected inB. burgdorferi strains isolated from the non-human-biting tickIxodes affinis and rodent hosts in the southeastern United States. We discovered that someospC alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration ofBorrelia species.