Rare and Susceptible: Hypermucoviscous Capsular 1 (K1) Serotype Klebsiella Pneumoniae Infective Endocarditis in a Patient with HIV-AIDS and Chronic Lymphocytic Leukemia

Hypermucoviscous (hv) Klebsiella pneumoniae strains are known to cause community-acquired infections that are serious, metastatic, and lethal. Patients with uncontrolled diabetes mellitus and people of Asian descent are predisposed to more severe disease. Infective endocarditis is an extremely rare complication of these infections. A 41-year-old Filipino male with HIV-AIDS and chronic lymphocytic leukemia presented with fever and symptoms of acute heart failure. He had hypotension, engorged neck veins, bibasal crackles, and a holosystolic murmur at the cardiac apex. Echocardiography showed an oscillating mass on the anterior mitral valve. Blood cultures grew hypermucoviscous K. pneumonia with positive string test and confirmed via multilocus sequence virulence typing. He improved with six weeks of intravenous antibiotics. This is the first case of (1) hv phenotype K. pneumoniae infective endocarditis, without other infectious foci, in a non-diabetic man with HIV-AIDS and CLL; and (2) an hv K. pneumoniae endocarditis patient with shock to have survived.