This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'M.C. organism in acute osteomyelitis ? \nSelect and explain. \nA. Staphylococcus aureus, B. Salmonella, C. Pseudomonas aeruginosa, D. Streptococcus pneumonia', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Staphylococcus aureus Acute osteomyelitis may be : - i) Primary (hematogenous) : - Organisms reach the bone through blood stream. ii) Secondary : - Organism gain entery directly through wound such as in compound fractures or surgical operation. Hematogenous osteomyelitis is the commonest form of osteomyelitis and most common source of bone and joint infection is hematogenous. It is caused most commonly by staphylococcus aureus. Other causative organisms are streptococcus, pneumococcus, and gram negative bacilli. Infection by pseudomonas becomes propoionally much more common in IV drug abuser. But, the most common organism is staphylococcus aureus.", 'role': 'assistant'}]