Lecture 4 -- Gram Positive & Negative Cocci

Question 1

Gram Positive Cocci

Answer 1

• Spherical / circular / round bacteria
• Thick peptidoglycan layer on cell wall
• LOOKS PURPLE

Question 2

Staphylococci

Answer 2

Gram-positive cocci (1 μm diameter) growing in grape-like clusters

Species :
- Staphylococcus epidermidis – Normal flora of skin & mucosae; occasionally pathogenic
- Staphylococcus aureus – Pathogenic, often found as normal flora
- Staphylococcus saprophyticus – In the environment and on skin, can cause urinary infections
- Staphylococcus aureus – Grows well on simple media (agar, blood-agar) producing 2-3 mm colonies in 24 h (37ºC)