Infectious endocarditis caused by Elizabethkingia spp.: Two case reports and a literature review

We report two cases of Elizabethkingia-related infective endocarditis, highlighting key risk factors such as prosthetic valve replacement. These cases underscore the need to consider endocarditis in the setting of persistent or recurrent bacteremia. Diagnosis proved challenging and required multiple imaging modalities, with positron emission tomography (PET) scan providing critical value when echocardiography was non-contributory. Management was complicated by the organism's intrinsic multidrug resistance and the rapid emergence of additional resistance during therapy. These cases emphasize the importance of combination antibiotic regimens, in which minocycline may play a key role. Due to its ability to rapidly adhere to and produce biofilm on prosthetic valves, our cases support the need for early surgical intervention to eradicate the biofilm and limit further resistance development. To better characterize this rare entity, we conducted a literature review of previously reported cases, which reinforces the diagnostic and therapeutic challenges associated with Elizabethkingia endocarditis.