Bacterial Classification

Bacterial Classification

Gram Positive Bacteria ‘2’ Cocci

‘4’ Bacilli ‘Rods’

Branching

1- Staphylococci

1- Actinomyces

2- Streptococci

2- Nocardia Spore-forming

Non Spore-forming

1- Clostridium

1- Corynebacterium

2- Bacillus

2- Listeria

Gram Negative Bacteria DiploCoccous

Spirochetes

Pleomorphic

Bacilli

- Neisseria

-Treponema

-Chlamydia

- The rest

- Borrelia

- Rickettsiae

- Leptospira

Cell-wall-less • Mycoplasma: - have only simple cell membrane - So, not either gram-positive or negative

Exceptions • Mycobacteria: - Weak gram-positive - Stain better with acid-fast stain • Spirochetes: - Gram negative - But, too small to be seen by the light microscope, can be seen with dark-field microscope.