IDENTIFICATION OF AN UNCULTIVABLE BORRELIA SPECIES IN THE HARD TICK AMBLYOMMA-AMERICANUM - POSSIBLE AGENT OF A LYME DISEASE-LIKE ILLNESS

Bites from the hard tick Amblyomma americanum are associated with a Ly me disease-like illness in the southern United States, To identify pos sible etiologic agents for this disorder, A. americanum ticks were col lected in Missouri, Texas, New Jersey, and New York and examined micro scopically. Uncultivable spirochetes were present in similar to 2% of the ticks. Borrelia genus-specific oligonucleotides for the flagellin and 16S rRNA genes were used for amplification of DNA. Products were o btained from ticks containing spirochetes by microscopy but not from s pirochete-negative ticks, Sequences of partial genes from spirochetes in Texas and New Jersey ticks differed by only 2 of 641 nucleotides fo r flagellin and 2 of 1336 nucleotides for 16S rRNA, Phylogenetic analy sis showed that the spirochete was a Borrelia species distinct from pr eviously characterized members of this genus, including Borrelia burgd orferi. Gene amplification could be used to detect these spirochetes i n ticks and possible mammalian hosts.