Brain abscess formation following cerebral infarction during treatment for hypervirulent Klebsiella pneumoniae...

Hypervirulent Klebsiella pneumoniae (hvKp) causes severe community-acquired infections and is associated with metastatic complications, including central nervous system infections. Brain abscess is a recognized manifestation of hvKp infection; however, reports describing the evolution of cerebral infarction into brain abscess during treatment for hvKp meningoencephalitis are limited. We report a case of rapidly progressive meningoencephalitis caused by hvKp characterized by the K2 serotype, rmpA/rmpA2 genes, and sequence type 65. Brain MRI on day 5 demonstrated cerebral infarction associated with cerebral vasospasm. Follow-up imaging on day 12 demonstrated brain abscess formation within the previously infarcted lesion. Notably, no typical remote focus of infection, such as a liver abscess, was identified, and blood cultures were negative. Intravenous ceftriaxone was continued for 8 weeks, followed by oral trimethoprim-sulfamethoxazole and subsequently levofloxacin. Serial MRI demonstrated gradual reduction of the abscess, with near-complete radiological resolution by day 72 and no evidence of recurrence up to day 93. Nevertheless, the patient remained neurologically impaired at the time of transfer. This case highlights that severe hvKp meningoencephalitis may be complicated by cerebral vasospasm, cerebral infarction, and subsequent brain abscess formation despite appropriate antimicrobial therapy. Serial neuroimaging may be important for detecting disease progression and determining the appropriate duration of antimicrobial treatment.