Answer:
Staphylococcus aureus.
Explanation:
Pneumonia may be defined as the medical condition in which the air sacs are inflamed in either or both of the lungs. The pus or fluid gets filled in the air sacs in case of pneumonia.
The pneumonia is caused by the bacteria Staphylococcus aureus. This bacteria is responsible to cause pneumonia in the host that are immunocompromised and has impaired granulocyte. This bacteria may enter through the infection or with contaminated water and food.
Thus, the answer is Staphylococcus aureus.