PetriKey

Bacterium

Treponema pallidum

Spirochete with serology vocabulary

trep-oh-NEE-muh PAL-ih-dum

bacteriaspirocheteserologysti

High-yield clue

Spirochete morphology + serology vocabulary is the core clue.

Overview

A spirochete used to teach corkscrew morphology, serologic-test vocabulary, and stage-based coursework associations.

Classification

  • Spirochete
  • Thin helical bacterium

Lab & identification clues

  • Dark-field microscopy vocabulary
  • Nontreponemal/treponemal serology concepts
  • Spirochete morphology

Associations

  • Syphilis coursework vocabulary
  • Congenital infection vocabulary
  • Public-health screening framing

Commonly confused with

  • Borrelia burgdorferi
  • Leptospira interrogans

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource