This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pediatrics
The sudden appearance of pneumothorax in a child suffering from pneumonia points to which etiology? 
Select and explain. 
A. Staphylococci, B. Streptococci, C. Mycoplasma, D. Klebsiella
A: Staphylococci
Answer: A: Staphylococci 
Explanation: Pneumonia caused by S. aureus may be primary or secondary after a viral infection such as influenza. Common symptoms and signs include high fever, abdominal pain, tachypnea, dyspnea, and localized or diffuse bronchopneumonia or lobar disease. S. aureus often causes a necrotizing pneumonitis that may be associated with early development of empyema, pneumatoceles, pyopneumothorax, and bronchopleural fistulas.Ref: Nelson Textbook of Paediatrics; 20th edition; Chapter 181; Staphylococcus