(227) Kingella Bacteremia: A Complication in the Aortic Graft Recipient

Introduction: Kingella Kingae (K. Kingae) is a gram-negative, facultative anaerobic coccobacillus increasingly reported in the US, though found in less than one percent of adults. This Kingella species, part of the HACEK group of bacteria, infrequently causes bacteremia and endocarditis. Kingella bacteremia poses challenges, especially with prosthetic devices or implanted grafts, due to its rarity and potential for serious complications. Here, we report a case of Kingella bacteremia in a patient who underwent aortic graft surgery in adolescence and developed this infection in adulthood.

Description: A 32-year-old male with a history of coarctation of the aorta surgically repaired as a child and aortic valve replacement presented with fever (102.6°F), chills, and weakness. CBC and CMP were unremarkable. Blood cultures identified Kingella Kingae in 2 out of 2 cultures. A transesophageal echocardiogram was unremarkable. A CTA of the chest revealed mild mural thrombus in the aortic stent graft. The patient received a 2-week course of meropenem due to concerns about future embolic events. Near the end of the hospital stay, it was determined that the patient would benefit from both IV antibiotics and anticoagulation, with outpatient follow-up. He was subsequently discharged and continued to attend follow-ups without further complications..

Discussion: Kingella kingae is a gram-negative coccobacillus that colonizes the oropharynx and is primarily known to cause musculoskeletal infections in children. However, it has been increasingly recognized as a cause of infective endocarditis in patients with predisposing cardiac conditions or prosthetic cardiac devices. In this case, the presence of a prior aortic root graft likely provided a breeding ground for K. kingae bacteremia and subsequent IE. The diagnosis of IE relies on a combination of clinical, microbiological, and echocardiographic findings. Transesophageal echocardiography is more sensitive than transthoracic echocardiography for assessing the extent of cardiac involvement  in patients with prosthetic cardiac devices. Although the diagnosis may be challenging due to the fastidious nature of the organism, prompt recognition of prosthetic devices or surgical implants is crucial in initiating appropriate diagnostic evaluation and antimicrobial therapy.