title: Absence of microbial adaptation to taurolidine in patients on home parenteral nutrition who develop catheter related bloodstream infections and use taurolidine locks.
abstract: OBJECTIVE
  Some home parenteral nutrition (HPN) patients develop catheter related bloodstream infections (CRBSI) despite using an anti-microbial catheter lock solution taurolidine. The aim of this study was to assess whether long-term use of taurolidine leads to selective growth of microorganisms with increased taurolidine minimum inhibitory concentrations (MICs).
  
  
  METHODS
  Bloodstream infections among 158 HPN patients with long-term taurolidine catheter locking were analyzed retrospectively. CRBSI-diagnosis was based on clinical symptoms, culture results, and absence of other sources of infections. CRBSIs were classified as definitive, probable or possible and exit site/tunnel/port or luminal infections. MICs were determined by broth microdilution.
  
  
  RESULTS
  Between January 2009 and April 2011, 14 patients developed at least one luminal CRBSI episode during long-term taurolidine catheter locking (median (range) = 451 (78-1394) days). Coagulase-negative Staphylococcus species or Staphylococcus aureus predominated among CRBSI-causing Gram-positive bacteria. Taurolidine MICs were 512 mg/l or less in 50% of these isolates (MIC50). Taurolidine MIC50 for Klebsiella pneumoniae and Escherichia coli, the most common CRBSI-causing Gram-negative bacteria, were 256 and 512 mg/l, respectively. Taurolidine MIC50 among CRBSI-causing Candida albicans were 2048 mg/l.
  
  
  CONCLUSIONS
  Adaptation of microorganisms to taurolidine has not yet emerged as a factor in the pathogenesis of CRBSI in HPN patients with long-term taurolidine catheter locking.
authors.affiliation: Intestinal Failure Unit, Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. E.Olthof@mdl.umcn.nl
authors.forename: E D
authors.initials: ED
authors.lastname: Olthof
authors.forename: R J
authors.initials: RJ
authors.lastname: Rentenaar
authors.forename: A J M M
authors.initials: AJ
authors.lastname: Rijs
authors.forename: G J A
authors.initials: GJ
authors.lastname: Wanten
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002176:Candida albicans / Q000187:drug effects; D055499:Catheter-Related Infections / Q000175:diagnosis / Q000209:etiology / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects; D005260:Female; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016331:Parenteral Nutrition, Home / Q000009:adverse effects*; D012189:Retrospective Studies; D013210:Staphylococcus / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013654:Taurine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013829:Thiadiazines / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D013829:Thiadiazines; D013654:Taurine; C012566:taurolidine