A case report of wrist arthritis caused by Gemella haemolysans

Background : Gemella haemolysans is a rare Gram-positive coccus causing systemic infections such as endocarditis. Osteoarticular involvement is exceptional, mainly reported in prosthetic infections or spondylodiscitis. Case Presentation : We describe the first documented case of septic arthritis of a native wrist due to G. haemolysans in a 45-year-old immunocompromised woman with end-stage renal disease, HIV-HBV coinfection, and untreated multiple myeloma. Diagnosis was confirmed by blood cultures and joint fluid aspiration, with bacterial identification via MALDI-ToF and susceptibility testing showing low MICs for amoxicillin. Despite this, initial treatment with amoxicillin alone failed to achieve clinical or biological improvement. The addition of clindamycin resulted in complete resolution of symptoms and normalization of inflammatory markers after five weeks of dual therapy. Conclusion : This case illustrates the potential limits of monotherapy with beta-lactams in native joint infections caused by G. haemolysans, especially in immunocompromised patients. The failure of amoxicillin may be explained by factors such as limited diffusion into joint tissues, the absence of surgical debridement, and the use of pharmacokinetic and pharmacodynamic breakpoints not specifically validated for this rare species. Early reassessment and combination therapy may be warranted, particularly in immunocompromised individuals.