Abstract:
INTRODUCTION : Bacillus species are often considered as contaminants when cultured from
clinical samples. Bacillus cereus may be a pathogen in certain circumstances and is known to
cause musculoskeletal infections. This report aims to educate clinicians and clinical
microbiology laboratories on B. cereus musculoskeletal infections and to heighten awareness
that Bacillus species should not always be dismissed as contaminants.
CASE PRESENTATION : We report the case of a patient who presented to a tertiary hospital in
Pretoria, South Africa, in November 2018 with B. cereus septic arthritis and underlying systemic
lupus erythematosus (SLE). The isolate would otherwise have been dismissed as a contaminant
had it not been for the crucial interaction between the laboratory and the treating clinicians.
To our knowledge, this is the first case report of septic arthritis caused by B. cereus in an SLE
patient where the organism was cultured from the joint specimen. Identification of the
organism was performed using matrix-assisted laser desorption/ionisation mass spectrometry.
MANAGEMENT AND OUTCOME : Definitive treatment was with intravenous vancomycin, continued
for four weeks, in addition to arthroscopy and management of the underlying SLE. The patient
had a good clinical outcome and regained full mobility.
CONCLUSION : Musculoskeletal infections, specifically septic arthritis caused by B. cereus, are
exceedingly rare infections. Immune suppression, trauma, prosthetic implants and invasive
procedures are important risk factors for B. cereus musculoskeletal infections. Close
collaboration with a multi-disciplinary team approach will effect the best outcome for
complicated patients with B. cereus infections.
