This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection of Bones & Joints, Subject name: Orthopaedics
Septic arthritis is caused by: 
Select and explain. 
A. N.gonorrhoea, B. E.coli, C. Mycobacterium tuberculosis, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans: d (All of the above) Ref: Bailey, 24,h ed, p. 420All the given organisms can cause septic arthritis in different age groups.Most common cause of septic arthritis - Staph aureus (in all age groups)More common in neonates- E. coli& Group B. StreptococciSickle cell anemia patients are susceptible to salmonella arthritis.Aerobic gram negative organisms cause discitis in elderly.Brucella & Mycobacterium TB are common in tropics.