Severe disseminated infection by hypermucoviscous Klebsiella pneumoniae successfully treated by intensive therapy with continuous hemodiafiltration using AN69ST: A case report and review of the literature.

Klebsiella pneumoniae (Kpn) is one of the most common gram-negative bacilli causing lung, urinary tract, and biliary tract infections. However, as a distinct entity from classic Kpn, hypervirulent Kpn causing liver abscess, endophthalmitis, and lung abscess with poor prognoses has been reported mainly in East and Southeast Asia since the mid-1980s. Although the definition of hypervirulent Kpn is unclear, the hypermucoviscosity of Kpn is considered an important feature of hypervirulence. We present a case of emphysematous pyelonephritis accompanied by septic shock and acute kidney injury caused by hypermucoviscous Kpn infection that was successfully treated by intensive treatment. A 70-year-old woman with type 2 diabetes mellitus was diagnosed with emphysematous pyelonephritis, and string test-positive Kpn was detected in blood and urine cultures and percutaneous catheter drainage fluid from the renal pelvis. The patient was treated with intensive therapies including antibiotics, ventilator management, and continuous hemodiafiltration (CHDF) using AN69ST, which can absorb cytokines. During the course of treatment, the infection was complicated by pyogenic spondylitis, which was cured by antimicrobial therapy, and the patient was transferred to another hospital for rehabilitation on day 119 after admission. Hypermucoviscous Kpn infection often has a severe course, and it is important to initiate multidisciplinary treatment at an early stage, including rifampicin, which is expected to inhibit the viscosity of hypermucoviscous Kpn. In the current case, immediate CHDF using AN69ST was also considered a life-saving treatment because it improved both volume overload and neutrophil-activated hypercytokinemia.