Group B Streptococcal sacroiliitis: case report and review.

Streptococcus agalactiae, or group B Streptococcus (GBS), is the major cause of neonatal meningitis and sepsis but is an uncommon infection in adults. GBS arthritis is rare, and axial involvement with sacroiliitis is even more uncommon. Microbiological diagnosis frequently relies upon positive blood cultures as synovial fluid cultures are usually negative. Severe joint damage may result due to delay in the initiation of antibiotic treatment.