Most common organisms that cause Septic Arthritis are - Staphylococci e.g. Staphylococcus aureus (most common cause), coagulase-negative Staphylococci - E. coli - Gonococci - Streptococci e.g. Streptococcus pyogenes, Streptococcus pneumoniae, Group B Streptococci - Haemophilus influenzae - Neisseria gonorrhoeae - Neisseria meningitides - Pseudomonas aeruginosa - M. Tuebrculosis - Salmonella spp. - Brucella spp. - Spirillium minus - Streptobacillus monifliformis