) complex is a diverse group of worldwide distributed bacteria that includes 18 named spirochete species and a still not named group proposed as genomospecies 2. Descriptions of new
species and variants continue to be recognized, so the current number of described
species is probably not final. Most of known spirochete species are considered to have a limited distribution. Eleven species from the B. burgdorferi s.l. complex were identified in and strictly associated with Eurasia (B. afzelii, B.