What is the difference between a bacterium and a spirochete?

Question

I remember wondering about this during a lecture when the professor kept mentioning spirochetes separately from regular bacteria. It sounded like they were completely different organisms, but I wasn’t sure. After digging into some references, I realized that spirochetes are indeed bacteria, but with very unique features that make them stand out. If you’ve ever been confused about how spirochetes differ from other bacteria, this breakdown clears it up.

in progress 0
Barry Mosley 2025-06-13T13:43:42+00:00 1 Answer 4 views
0

Answer ( 1 )

  1. fleming
    0
    2025-07-13T14:47:26+00:00
    Reply

    Are spirochetes bacteria?

    Yes, spirochetes are a phylum of bacteria. The comparison is really between spirochetes and the more familiar rod or cocci shaped bacteria you see on agar plates.

    What makes spirochetes special

    • Shape and motility: Long, thin, helical cells that move with a corkscrew motion thanks to periplasmic flagella (axial filaments).
    • Cell envelope: Double membrane like Gram‑negative bacteria, but the outer membrane of many species lacks LPS.
    • Endoflagella location: Flagella sit inside the periplasm instead of sticking out, letting the cell drill through viscous media like mucus or connective tissue.
    • Size: Very thin (about 0.1–0.3 μm) so they can pass through filters that stop most other bacteria.
    • Examples: Treponema pallidum (syphilis), Borrelia burgdorferi (Lyme disease), Leptospira interrogans (leptospirosis).

    Similarities to other bacteria

    They still have peptidoglycan, 70 S ribosomes, a circular chromosome and they respond to antibiotics that target bacterial processes, for instance doxycycline or penicillin.

    Bottom line

    A spirochete is a bacterium with a corkscrew shape and internal flagella that give it unique motility and some diagnostic quirks. Thats pretty much the whole story.

Leave an answer

Browse
Browse