Streptococcus gallolyticus prosthetic joint infection associated with undiagnosed colonic malignancy

Streptococcus gallolyticus is a group D streptococcus which was previously classified as part of the S. bovis/S. equinus complex. It is a rare pathogen in prosthetic joint infection but has been demonstrated to have a strong association with colorectal carcinoma. In this case, a patient with no symptomatology suggestive of colorectal carcinoma presented with a S. gallolyticus prosthetic joint infection. Awareness of the association prompted investigation and subsequent diagnosis of colorectal carcinoma which was successfully treated prior to two-stage revision knee replacement. Level of evidence V.