Cerebral Microhemorrhages Secondary to a Hypervirulent Klebsiella Pneumoniae Infection.

A 44-year-old man with a history of diabetes taking no medication was admitted to our hospital because of fever and consciousness disturbance. Computed tomography showed the presence of a liver abscess (Picture A) and a septic pulmonary embolism (Picture B). Brain magnetic resonance imaging revealed multiple abscesses on diffusion-weighted images (Picture C) and multiple microhemorrhages on susceptibility-weighted images (Picture D). Magnetic resonance angiography showed no abnormalities (Picture E). The patient showed nuchal rigidity, and a lumbar puncture revealed the concurrence of bacterial meningitis. In addition, left endophthalmitis was observed. Blood and liver abscess cultures revealed serotype K1 hypermucoviscous Klebsiella pneumoniae carrying both rmpA and magA genes, which led to a diagnosis of hypervirulent Klebsiella pneumoniae (hvKP) infection. The patient developed disseminated intravascular coagulation, which rapidly improved after performing percutaneous transhepatic abscess drainage and antibiotic therapy. On the other hand, cerebral abscesses and microbleeds worsened over then next 4 weeks. After continuing antibiotic therapy for 8 weeks, the patient completely recovered. Although multiple cerebral hemorrhages are rarely seen in bacteremia cases, except for cases of infective endocarditis (IE), we assume that this patient most likely did not have IE, since transthoracic echocardiography showed no evidence of either hvKP vegetation nor valvular disease or congenital heart disease, which can be risk factors for IE. The findings of the present case are indicative of the severe invasiveness of hvKP leading to the onset of microvasculopathies such as vasculitis and mycotic aneurysm formation, which can cause cerebral hemorrhages even in the absence of IE (1,2).

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The authors state that they have no Conflict of Interest (COI).