Klebsiella aerogenes Causing Mitral Valve Infective Endocarditis With Multiple Septic Emboli to the Brain: A Case Report.

Klebsiella aerogenes is a Gram-negative bacterium commonly associated with urinary tract infections (UTIs); however, it can occasionally cause bloodstream infections and, rarely, infective endocarditis (IE). Severe complications related to K. aerogenes bloodstream infections, such as systemic embolization, have been described in the literature. In this report, we describe a case of K. aerogenes IE in an elderly male patient who initially presented to urgent care with a UTI. He had been diagnosed and prescribed a course of oral antibiotics; however, the treatment failed due to antimicrobial resistance. This led to the development of bacteremia and sepsis requiring hospital admission. He later developed endocarditis as confirmed by echocardiography, which was complicated by mitral regurgitation, respiratory failure, and multiple embolic central nervous system (CNS) strokes. He was treated with intravenous (IV) antibiotics and assessed by cardiac surgery, though operative management was deferred until his overall condition improved. This case underscores the importance of early recognition and timely management of IE in patients with persistent Klebsiella bacteremia unresponsive to initial therapy, emphasizing a multidisciplinary approach to achieve optimal outcomes, especially when dealing with such rare causative organisms.