9 ▁belong ▁to ▁the ▁rela ps ing ▁fe ver ▁group , ▁and ▁two ▁are ▁members ▁of ▁a ▁gen et ically ▁distinct ▁third ▁group ▁typically ▁found ▁in ▁re pt iles . ▁The ▁L yme ▁disease ▁group ▁has ▁been ▁moved ▁to ▁their ▁own ▁genus , ▁Bor elli ella , ▁but ▁this ▁change ▁is ▁not ▁yet ▁widely ▁accepted . ▁This ▁b acter ium ▁uses ▁hard ▁and ▁soft ▁t icks ▁and ▁l ice ▁as ▁vectors . ▁Test ing ▁for ▁the ▁presence ▁of ▁the ▁b acter ia ▁in ▁a ▁human ▁includes ▁two - t ier ed ▁ser ological ▁testing , ▁including ▁imm uno ass ays ▁and ▁imm un ob lot ting . ▁▁ ▁Bi ology ▁Bor rel ia ▁species ▁are ▁members ▁of ▁the ▁family ▁S pi ro cha et aceae , ▁so ▁present ▁the ▁characteristic ▁sp iro ch ete ▁( sp iral ) ▁shape . ▁Most ▁species ▁ ▁are ▁oblig ate ▁an a er ob es , ▁although ▁some ▁are ▁aer ot ol er ant . ▁Bor rel ia ▁species ▁have ▁an ▁outer ▁memb rane ▁that ▁contains ▁a ▁subst ance ▁similar ▁to ▁li pop ol ys ac char ides , ▁an ▁inner ▁memb rane , ▁and ▁a ▁layer ▁of ▁pe pt id og ly can ▁in ▁a ▁peri pl asm ic ▁space , ▁which ▁class ifies ▁them ▁as ▁Gram - negative . ▁However , ▁this ▁result ▁is ▁not ▁easily ▁visual ized ▁using ▁Gram ▁st aining . ▁They ▁are ▁typically ▁ 2 0 – 3 0 ▁ μ m ▁long ▁and ▁ 0 . 2 – 0 . 3