Morphology and Cultural characters of Staphylococcus

Morphology and Cultural characters of Staphylococcus

Morphology of Staphylococcus:

ð  Shape : Spherical rounded

ð  Size  :     I   µm in diameter.

ð  Arranged:  gram-like clusters and also in pair or short chain.

ð  Flagella:     Absent.

ð  Spore: Absent.

ð  Capsule: Absent but some strain have capsule.

ð  Staining:  They are Gram positive.

Cultural characters Staphylococcus:

1.       Aeorbic and microaerophilic

2.       Optimum Ph: 7.4to 7.6

3.       Optimum temperature :37°C.

4.       Pigment production takes place in solid media but not in liquid media.

5.       Growth characters are common bacteriological media.

ð  Nutrient agar: Colonies are circular, concave, 2-4 mm in diameter with shining surface and may be pigmented, golden yellow ,white or lemon yellow .

ð  Blood agar: Colonies are large with zone of haemolysis.

ð  Nutrient media: Organisms grow with uniform turbidity.

ð  Gelatine and coagulater serum are liquefied.

ð  Selective media: Media incorporating  10-15% sodium chloride act as selective media e.g.10% salt agar ,10% salt broth or 7% salt in milk agar.

ð  Indicator media :

a)Nutrient agar with 1% glycerol mono-acetate produces with enhanced pigment productions.

b)Nutrient agar containing mercuric chloride.