Metachromatic granules are found in:
Metachromatic granules

It is a type of intracytoplasmic inclusion characteristically seen in diphtheria bacilli.
Also known as volutin or metachromatic or Babes Ernst granules.
Strongly basophilic bodies consist of polymetaphosphate.
They are reservoir of energy and phosphate.
They are most frequent in cells growing under nutritionally deficient condition.

Remember :

Metachromatic granules are also seen in B.pertussis (whooping cough).
Diphtheria
Mycoplasma
Chlamydia
Staphylococcus