Douglas Harper's Etymology Dictionary
strepto-
word-forming element used in science to mean "twisted," from Latinized comb. form of Greek streptos "twisted, easy to bend, pliant," verbal adjective of strephein "to turn, twist," from PIE *streb(h)- "to wind, turn" (see strophe).
Wiktionary
strepto-
pre. 1 twisted 2 having the form of a twisted chain