Failure of cloxacillin in treatment of a patient with borderline oxacillin-resistant Staphylococcus aureus endocarditis.

Clinical evidence for failure with beta-lactam therapy has been lacking for patients with borderline oxacillin-resistant Staphylococcus aureus (BORSA) infections. We describe a failure of cloxacillin for a patient with endocarditis due to BORSA. The isolate also had false-negative thermonuclease and coagulase test results.

Pyogenic liver abscess caused by hypermucoviscous Klebsiella pneumoniae.

Community-acquired primary pyogenic liver abscess (PLA) caused by Klebsiella pneumoniae is an emerging infectious entity, with cases reported in the scientific literature over the past 15 y mainly from Taiwan and Asia, but also from Europe and North America. We describe a case of PLA caused by the hypermucoviscous, K1 capsular serotype of Klebsiella pneumoniae in a Canadian man and highlight the unique features of this increasingly common cause of liver abscess.