This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal infections, Subject name: Anatomy
Post traumatic osteomyelitis causing organism is 
Select and explain. 
A. Staphylococcus aureus, B. Staphylococcus pyogenes, C. E.coli, D. Pseudomonas
A: Staphylococcus aureus
Answer: A: Staphylococcus aureus 
Explanation: Staphylococcus aureus is the most common causative organism in all age groups. Salmonella is the commonest organism in sickle cell anemia patients(diaphyseal). Psuedomonas aeruginosa is the commonest organism in drug abusers. ref : maheswari 9th ed