title: Clinical and microbiological characteristics of peritoneal dialysis-related peritonitis caused by Klebsiella pneumoniae in southern Taiwan.
abstract: OBJECTIVE
  Gram-negative peritonitis is a frequent and serious complication of peritoneal dialysis (PD). No previous reports have focused on Klebsiella pneumoniae infection. The aim of this study was to investigate the host and bacterial factors associated with K. pneumoniae PD-related peritonitis.
  
  
  METHODS
  We retrospectively studied K. pneumoniae PD-peritonitis cases treated at a university hospital in southern Taiwan during 1990-2011, and analyzed the clinical features and outcomes and bacterial characteristics of serotypes, hypermucoviscosity (HV), and virulence-associated genes such as wabG, uge, and rmpA in K. pneumoniae PD-related peritonitis. Fifty-four isolates of K. pneumoniae-related community-acquired urinary tract infection (UTI) and 76 morphologically different nonpathogenic K. pneumoniae isolates from healthy adults were used as controls.
  
  
  RESULTS
  K. pneumoniae was the second most common monomicrobial pathogen causing Gram-negative PD-related peritonitis (n = 13, 2.7%), and the most common pathogen involved in polymicrobial peritonitis (16/43, 37.2%) and associated with high catheter removal rate (7/16, 43.8%). Compared with Escherichia coli peritonitis cases, patients with monomicrobial K. pneumoniae peritonitis also had insignificantly higher incidence of sepsis/bacteremia [n = 5 (38%), p = 0.11] and a higher mortality rate [n = 3 (23%), p = 0.36]. The prevalence of K1/K2 (n = 1, 7.7%) serotypes was low, but there was a higher prevalence of serotype K20 (n = 3, 23.1%) in K. pneumoniae isolates derived from monomicrobial PD-related peritonitis compared with control groups. HV phenotype (p < 0.001) and rmpA genotype (p = 0.007) were absent in the peritonitis group.
  
  
  CONCLUSIONS
  This is the first study focused on clinical and microbiological characteristics of K. pneumoniae PD-related peritonitis. K. pneumoniae was a common Gram-negative pathogen causing monomicrobial and polymicrobial PD-related peritonitis in southern Taiwan. The bacterial characteristics with low percentage of capsular serotype K1/K2, no significant HV, and absence of rmpA suggest a different pathogenesis in K. pneumoniae PD-related peritonitis compared with that in UTI and liver abscess.
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Wei-Hung
authors.initials: WH
authors.lastname: Lin
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Chin-Chung
authors.initials: CC
authors.lastname: Tseng
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: An-Bang
authors.initials: AB
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Deng-Chi
authors.initials: DC
authors.lastname: Yang
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Shian-Wen
authors.initials: SW
authors.lastname: Cheng
authors.affiliation: Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan. Electronic address: wangmc@mail.ncku.edu.tw.
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Wang
authors.affiliation: Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan. Electronic address: jjwu@mail.ncku.edu.tw.
authors.forename: Jiunn-Jong
authors.initials: JJ
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000302:isolation & purification*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology; D012189:Retrospective Studies; D012703:Serotyping; D013624:Taiwan / Q000453:epidemiology; D016896:Treatment Outcome; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
chemical_list: D037521:Virulence Factors
keywords: Hypermucoviscosity; Klebsiella pneumoniae; Peritoneal dialysis; Peritonitis; Virulence factor