title: Invasive liver abscess syndrome caused by Klebsiella pneumoniae with definite K2 serotyping in Japan: a case report.
abstract: BACKGROUND
  Klebsiella pneumonia is a well-known human pathogen, and recently, a distinct invasive syndrome caused by K. pneumoniae serotypes K1 and K2 has been recognized in Southeast Asia. This syndrome is characterized by primary liver abscess and extrahepatic complications resulting from bacteremic dissemination. We report the first adult case of primary liver abscess caused by the definite K2 serotyped pathogen, with endogenous endophthalmitis in Japan.
  
  
  METHODS
  A 64-year-old woman was admitted to a nearby hospital for a high fever and diarrhea. She had visual loss of her right eye, renal dysfunction, and thrombocytopenia within 24 h from admission. She was transferred to our institution. On admission, she had no alteration of mental status and normal vital signs; however, she had almost complete ablepsia of the right eye. Laboratory data showed severe inflammation, liver dysfunction, thrombocytopenia, an increased serum creatinine level, and coagulopathy. Computed tomography showed a low density area in the right lobe of the liver. Invasive liver abscess syndrome probably caused by K. pneumonia was highly suspected and immediately administered broad-spectrum antibiotics for severe sepsis. Concurrently, endogenous endophthalmitis was diagnosed, and we performed vitrectomy on the day of admission. The blood culture showed K. pneumoniae infection. Percutaneous drainage of the liver abscess was also performed. Although she was discharged in a good general condition on day 22, she had complete ablepsia of the right eye. The K2A gene was detected by polymerase chain reaction (PCR), which is consistent with the K2 serotype. PCR was also positive for the virulence-associated gene rmpA. Final diagnosis was invasive liver abscess syndrome caused by K2 serotype K. pneumonia.
  
  
  CONCLUSIONS
  Although the primary liver abscess caused by K. pneumoniae with a hypermucoviscous phenotype is infrequently reported outside Southeast Asia, physicians should recognize this syndrome, and appropriate diagnosis and treatment is essential for saving patients' lives and preserving organ function, especially for visual acuity.
authors.affiliation: Department of Emergency and Critical Care Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.|Department of Surgery, Yamagata Prefectural Central Hospital, 1800 Aoyagi, Yamagata, 990-2292, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Seo
authors.affiliation: Department of Emergency and Critical Care Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. kudodaisuke@med.tohoku.ac.jp.|Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan. kudodaisuke@med.tohoku.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kudo
authors.affiliation: Division of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Department of Microbiology and Infectious Diseases, Nara Medical University, 840 Shijo-machi, Kashihara, 634-8521, Japan.
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yano
authors.affiliation: Division of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Aoyagi
authors.affiliation: Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Omura
authors.affiliation: Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.|Department of Neurology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Shigemi
authors.initials: S
authors.lastname: Irino
authors.affiliation: Division of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kaku
authors.affiliation: Department of Emergency and Critical Care Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.|Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kushimoto
keywords: Endogenous endophthalmitis; K2 serotype; Klebsiella pneumoniae; Liver abscess