Table 2.

Microbiology of septic arthritis cases.

OrganismN (%)N (%) from Synovial Fluid
Gram-positive organisms
  Staphylococcus aureus115 (46.3)89/115 (77.4)
  Coagulase-negative staphylococci8 (3.2)7/8 (87.5)
  Beta hemolytic streptococci30 (12.0)23/30 (76.7)
    Group A12 (4.8)9/12 (75)
    Group B9 (3.6)7/9 (77.8)
    Group C5 (2.0)4/5 (80)
    Group G4 (1.6)3/4 (75)
  Streptococcus pneumoniae5 (2)4/5 (80)
  Streptococcus gordonii2 (0.8)2/2 (100)
  Propionibacterium acnes10 (4)9/10 (90)
  Enterococcus faecalis5 (2)5/5 (100)
Gram-negative organisms
  Escherichia coli7 (2.8)5/7 (71.5)
  Neisseria gonorrhoea2 (0.8)2/2 (100)
  Neisseria meningitidis2 (0.8)2/2 (100)
  Pseudomonas aeruginosa4 (1.6)3/4 (75)
  Pasteurella multocida2 (0.8)0/3 (0)
  Mixed organisms*7 (2.8)6/7 (85.7)
  Other**3 (1.2)2/3 (66.7)
  No organism43 (17.3)

  • ↵* Anaerobic and aerobic flora (3), coagulase negative staphylococci plus Group C streptococcus (1), P. acnes and E. coli (1), P. acnes and Corynebacterium sp. (1), Pasturella pneumotropica (1).

  • ↵** Haemophilus influenzae, Achromobacter xylosoxidans, Aerococcus urinae.