Cocci

Definition

Cocci are spherical or oval-shaped bacteria. They can exist as single cells, in pairs, chains, or clusters.

5 Must Know Facts For Your Next Test

1. Cocci include both Gram-positive and Gram-negative species.
2. Staphylococcus and Streptococcus are common genera of Gram-positive cocci.
3. Gram-positive cocci have a thick peptidoglycan layer in their cell walls.
4. Cocci can cause various infections, including pneumonia, strep throat, and skin infections.
5. Identification of cocci morphology is crucial for diagnosing bacterial infections.

Review Questions

• What structural characteristic defines cocci?
• Name two common genera of Gram-positive cocci.
• Why is the identification of cocci important in medical microbiology?

Related terms

Bacilli:

Rod-shaped bacteria that can be either Gram-positive or Gram-negative.

Peptidoglycan:

A polymer that forms a protective layer making up the cell wall of most bacteria.

Gram Staining:

A method used to differentiate bacterial species into Gram-positive and Gram-negative groups based on their cell wall composition.