Culture-Negative Endocarditis in an Immunocompromised Patient: A Case of Suspected Bartonella and Coxiella Co-Infection.

We present the case of a 23-year-old man with a previous deceased-donor renal transplant maintained on tacrolimus and prednisone who developed culture-negative endocarditis (CNE) of the mitral and aortic valves. He was suspected of being co-infected with Bartonella henselae and Coxiella burnetii, confirmed with serology testing. He was successfully managed with appropriate antibiotics and dual valve replacement.