Usually initial therapy is empirical. If sufficient reason to suspect influenza, one might consider oseltamivir. In case of legionellosis, erythromycin or fluoroquinolone. A third generation cephalosporin (ceftazidime) + carbapenems (imipenem) + beta lactam & beta lactamase inhibitors (piperacillin/tazobactam)
Hospital-acquired pneumonia
Community-acquired pneumonia
Ventilator-associated pneumonia
Idiopathic pneumonia syndrome
Pneumococcal pneumonia
Bacterial pneumonia
Hantavirus pulmonary syndrome
Aspiration pneumonia