Vibrio, Spirillum and Spirochete Some bacteria are shaped like long rods twisted into spirals or helices; they are called vibrios (like commas or incomplete spirals), spirilla if rigid and spirochetes when flexable. vibrio spirillum spirocheteVibrio, Spirillum and Spirochete Some bacteria are shaped like long rods twisted into spirals or helices; they are called vibrios (like commas or incomplete spirals), spirilla if rigid and spirochetes when flexable. vibrio spirillum spirochete