Pneumothorax could be a complication of –
Staphylococcal pneumonia
Pneumococcal pneumonia
Klebsiella pneumonia
Viral pneumonia
Staphylococcal pneumonia is the most common cause of (amongst all pneumonia)

Purulent pericarditis
Pneumatoceles
Pneumothorax
Lung abscess
Empyema
Other organisms commonly causing empyma → Streptococcus pyogenes, Pneumococci