This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'Acute haematogenous osteomyelitis is commonly caused by \nSelect and explain. \nA. Staph, aureus, B. Strepto. pneumoniae, C. E. coli, D. Pneumococcus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A. i.e. (Staph, aureus) (197 - Ananthanaryan 7th)* Acute haematogenous osteomyelitis - causal organism is usually Staph, aureus, less often one of the other Gram positive cocci such as Streptococcus. Pyogenes or S. pneumoniae* Organism usually settles in the metaphysis most often in the proximal tibia or in the distal and proximal ends of the femur1. Staphylococcal toxic syndrome is due to Enterotoxin B & C**2. Pantone Valentine leucocitin is seen in - Staphylococci**3. The antibody marker in serum for Staph.endocarditis is - Antiteichoic acid**', 'role': 'assistant'}]