title: In vivo antibiofilm effect of cerium, chitosan and hamamelitannin against usual agents of catheter-related bloodstream infections.
abstract: OBJECTIVE
  Catheter-related bloodstream infections (CRBSIs) are common healthcare-associated infections associated with increased morbidity and medical costs. Antiseptic- and antibiotic-coated central venous catheters (CVCs) have been proposed to reduce the incidence of CRBSIs, with variable success. The aim of this study was to determine the in vivo antibiofilm activity of biocompatible and inexpensive compounds, such as cerium nitrate, chitosan and hamamelitannin, against usual agents of CRBSIs.
  
  
  METHODS
  The antibiofilm effect of cerium nitrate, chitosan and hamamelitannin was tested against Staphylococcus epidermidis, Staphylococcus aureus, Acinetobacter baumannii and Candida albicans in a mouse foreign body infection model, using polyurethane catheter segments. Biofilm formation was assessed with a crystal violet assay to quantify the total biomass, with a tetrazolium reduction assay to quantify the metabolic activity and with scanning electron microscopy.
  
  
  RESULTS
  At subinhibitory concentrations, cerium nitrate significantly reduced biofilm formation by C. albicans, chitosan significantly decreased biofilm formation by S. epidermidis and C. albicans, and hamamelitannin significantly inhibited all bacterial biofilms.
  
  
  CONCLUSIONS
  The in vivo antibiofilm effect of cerium nitrate against C. albicans and of chitosan against C. albicans and S. epidermidis, at subinhibitory concentrations, makes them promising alternatives to coat CVCs. Moreover, the microbicidal effect on a wider range of CVC colonizers was previously reported in vitro for both compounds, at higher concentrations. For all bacterial strains, the highest in vivo antibiofilm efficacy was achieved with hamamelitannin. For A. baumannii, this is the first report of in vivo inhibition.
authors.affiliation: Department of Microbiology, Faculty of Medicine,  University of Porto, Porto,  Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Cobrado
authors.forename: A
authors.initials: A
authors.lastname: Silva-Dias
authors.forename: M M
authors.initials: MM
authors.lastname: Azevedo
authors.forename: C
authors.initials: C
authors.lastname: Pina-Vaz
authors.forename: A G
authors.initials: AG
authors.lastname: Rodrigues
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000254:growth & development; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology; D055499:Catheter-Related Infections / Q000188:drug therapy* / Q000382:microbiology; D002563:Cerium / Q000494:pharmacology* / Q000627:therapeutic use; D048271:Chitosan / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D006601:Hexoses / Q000494:pharmacology* / Q000627:therapeutic use; D051379:Mice; D008807:Mice, Inbred BALB C; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000254:growth & development
chemical_list: D000890:Anti-Infective Agents; D006601:Hexoses; C032786:cerium nitrate; D002563:Cerium; D005707:Gallic Acid; D048271:Chitosan; C093412:hamamelitannin