Lone Star Tick-Infecting Borreliae Are Most Closely Related to the Agent of Bovine Borreliosis

Abstract

Although Borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing Lyme disease or relapsing fever remains undescribed. We tested the previously published hypothesis that spirochetes infecting Lone Star ticks (Amblyomma americanum) may comprise B. theileri by analyzing the 16S ribosomal DNAs (rDNAs) and flagellin genes of these spirochetes. B. theileri, the Amblyomma agent, and B. miyamotoi formed a natural group or clade distinct from but most closely related to that of the relapsing fever spirochetes. B. theileri and the Amblyomma agent were 97 and 98% similar at the nucleotide level within the analyzed portions of the 16S rDNA and the flagellin gene respectively, suggesting a recent divergence. The agent of bovine borreliosis might be explored as a surrogate antigen for the as-yet-uncultivatable Amblyomma agent in studies designed to explore the etiology of a Lyme disease-like infection associated with Lone Star ticks.

First Culture Isolation of Borrelia lonestari , Putative Agent of Southern Tick-Associated Rash Illness

“…Our LS-1 isolate 16S rRNA gene sequence matched one of the two published sequences for B. lonestari at three of these base positions and both B. lonestari sequences at the fourth position (base 522) (10). The published sequence for B. barbouri contained a single base difference at position 522, but because this was a partial sequence (355 bp) that did not include bases 698, 1025, and 1201, nucleotide similarity could not be evaluated at those positions (41). While it is important to note them, these differences are minor, and both the 16S rRNA and flagellin B gene sequences of the LS1 spirochetes support the identification of the organisms we have cultured as B. lonestari.…”

Glycerophosphodiester Phosphodiesterase Gene ( glpQ ) of Borrelia lonestari Identified as a Target for Differentiating Borrelia Species Associated with Hard Ticks (Acari:Ixodidae)

“…A glpQ ortholog has never been found in spirochetes that cause LD (14). Others have shown that B. lonestari, B. miyamotoi, and the agent of bovine borreliosis, Borrelia theileri, form a sister group based on 16S rDNA and fla sequence analyses (13). DNA evidence of another RFG spirochete (Yale spirochete), also closely related to B. miyamotoi, has been obtained from Ixodes scapularis (16).…”

“…Evidence suggests that persons in these regions bitten by the hard tick, Amblyomma americanum, who develop a red, expanding rash with central clearing (indistinguishable from erythema migrans, the hallmark rash of LD) are infected with a spirochete named Borrelia lonestari (3,4,8,18 (14). With these data, and given that B. lonestari is more closely related to RFG spirochetes than to LD spirochetes based on 16S ribosomal DNA (rDNA) and fla analyses (3,4,7,8,13), we decided to look for an ortholog of glpQ in B. lonestari-positive tick DNA. The 16S rRNA and fla genes are highly conserved and are present in all Borrelia species, making them ill suited for development of rapid, differential diagnostic assays.…”

flaB Gene as a Molecular Marker for Distinct Identification of Borrelia Species in Environmental Samples by the PCR-Restriction Fragment Length Polymorphism Method

“…Those spirochetes are divided into two main groups: relapsing fever (RF) borreliae, transmitted by "soft ticks" (Argasidae), and the Borrelia burgdorferi sensu lato complex, also known as the Lyme disease (LD) borreliae, propagated by "hard ticks" (Ixodidae) (10). The host and vector specificities of the RF complex members facilitate their identification, with the exception of B. miyamotoi, which appears on three continents and which is transmitted by different tick species on each (3,14,15).…”