MacConkey's Medium - Composition and bacteria cultured

MacConkey's Medium:

Composition:
1. Nutrient agar
2. Bile salt (sodium taurocholate)
3. Lactose
4. Neutral red (indicator)

Container:
Petri dish

Colour:
Transparent, reddish-brown or pink colour

Consistency:
Solid medium.

Micro-organism cultured?

It is used for:
1. growth and isolation of bacteria of family Enterobacteriaceae and to differentiate between lactose fermenters, non-lactose fermenters and late lactose fermenters.

Lactose Fermenters: form pink colonies, for example; E. coli, Klebsiella species, Enterobacter species
Non-lactose fermenters: from colorless colonies, for example, shigella species except shigella sonnie, salmonella species, proteus species and pseudomanas species.
Late lactose fermenters: form pink colonies after 2-3 days of inoculation. for example, Vibrio cholera, Serratia, Citrobacter, Shigella sonnei.

Important Culture Media:

a) Nutrient agar

b) Blood agar

c)Chocolate agar

d)McConkey's Medium

e) Lowenstein Jensen (LJ) medium

f) Loeffler's Coagulated Medium

g) Robertson's cooked meat medium

h) Triple sugar iron (TSI) medium

i) Christensen's Urea Medium

j) Simmon Citrate Medium

k) Peptone Water

l) Nutrient Broth

m) Sugar Media