A 55-year-old diabetic patient presents with fever, breathlessness and dry cough for 1 week. He also complains of headache, myalgia, diarrhea and vomiting. On examination, he is febrile with a temperature of 39 C, respiratory rate of 28, heart rate of 100 bpm, regular B.P 120/70 mmHg, O2 Saturation of 90% on room air. Chest examination shows decreased breath sounds bilaterally with bilateral crackles. His biochemical profile reveals hyponatremia and abnormal liver function test. Chest x-ray shows bilateral pulmonary infiltrate consistent with pneumonia. What is the most likely causative organism of pneumonia in this patient?