However pleomorphic bacteria can assume several shapes, following are the three basic bacterial shapes:
- Coccus (plural-cocci) : spherical
- Bacillus (plural-bacilli) : rod-shaped
- Spiral : twisted
Arrangements of Cocci
- Diplococci : Cocci that remain in pairs after dividing.
- Streptococci : Cocci that remain in chains, like beads on a string.
- Tetrads : The cocci that are arranged in packets of four cells, as the cells divide in two plains.
- Sarcinae : Cocci that divide in three planes and remain in groups cube like groups of eight.
- Staphylococci : Cocci that divide in multiple planes and form grape like clusters or sheets.
Arrangements of Bacilli
- Diplobacilli : Bacilli that remain in pairs after dividing.
- Streptobacilli : Bacilli that remain arranged in end-to-end chains.
- Coccobacilli : Bacilli that are so short and fat which look like cocci.
- Vibrios : Bacteria that are curved or comma-shaped.
- Spirilla : Bacteria that have a helical shape and fairly rigid bodies.
- Spirochetes : Bacteria that have a helical shape and flexible bodies.