What color is Staphylococcus aureus on MacConkey Agar?
Colony Morphology on MacConkey Agar
| Organism | Colour | Remarks |
|---|---|---|
| Escherichia coli | red/pink | non-mucoid |
| Aerobacter aerogenes | pink | mucoid |
| Enterococcus species | red | minute, round |
| Staphylococcus species | pale pink | opaque |
What plates does Staph aureus grow on?
aureus – individual colonies on agar are round, convex, and 1-4 mm in diameter with a sharp border. On blood agar plates, colonies of Staphylococcus aureus are frequently surrounded by zones of clear beta-hemolysis.
What type of bacteria grow on Mac plates?
MacConkey agar (MAC) is a bacterial culture medium named after bacteriologist Alfred T. MacConkey (1861-1931). MacConkey agar is a selective and differentiating agar that only grows gram-negative bacterial species; it can further differentiate the gram-negative organisms based on their lactose metabolism.
Why does Staphylococcus epidermidis not grow on MacConkey Agar?
The pink color of the bacterial growth indicates E. coli is able to ferment lactose. Quadrant 3: Absence of growth indicates the organism, Staphylococcus epidermidis, is inhibited by bile salts and crystal violet and is a gram-positive bacterium.
Does Staphylococcus aureus grow on MacConkey?
MacConkey agar selects for organisms like Escherichia coli (Gram negative bacilli) while inhibiting the growth of organisms like Staphylococcus aureus (Gram positive cocci).
What would be the expected appearance of Staphylococcus aureus on MacConkey agar?
MacConkey Agar without Crystal Violet Staphylococci produce pale pink to red colonies and enterococci produce compact tiny red colonies either on or beneath the surface of the medium.
Does Staphylococcus aureus grow on MacConkey Agar?
Does Staphylococcus aureus grow on blood agar?
On blood agar plates, colonies of Staphylococcus aureus are frequently surrounded by zones of clear beta-hemolysis. MRSA is able to grow on this media and produce colonies of certain color, depending on used pH indicator (in this picture pink).
Does Staph epidermidis grow on Mac?
MacConkey agar selects for organisms like Escherichia coli (Gram negative bacilli) while inhibiting the growth of organisms like Staphylococcus aureus (Gram positive cocci). The plate on the left has Staphylococcus epidermidis growing.
Does Enterobacter aerogenes grow on Mac?
Enterobacter, Cronobacter, and Pantoea spp. are nonfastidious in nature and grow on blood and chocolate agar and selective media for enteric bacteria. On MacConkey agar, E. cloacae and E.
