title: Prevention of catheter-related Pseudomonas aeruginosa infection by levofloxacin-impregnated catheters in vitro and in vivo.
abstract: BACKGROUND
  Implanted medical catheter-related infections are increasing, hence a need for developing catheter polymers bonded to antimicrobials. We evaluated preventive effects of levofloxacin-impregnated catheters in catheter-related Psuedomonas aeruginosa (strain PAO1) infection.
  
  
  METHODS
  Drug release from levofloxacin-impregnated catheters was measured in vitro. Levofloxacin-impregnated catheters and polyvinyl chloride (PVC) catheters were immersed in 5 ml 50% Luria Bertani medium containing 10(8) CFU/ml Pseudomonas aeruginosa then incubated for 6, 12, 24 or 48 hours at 37°C when bacteria adhering to the catheters and bacteria in the growth culture medium were determined. Impregnated and PVC catheters were singly implanted subcutaneously in mice, 50 µl (10(7)CFU) of PAO1 was injected into catheters. After the first and fifth days challenge, bacterial counts on implanted catheters and in surrounding tissues were determined microbiologically. Bacterial colonization and biofilm formation on implanted catheters were assessed by scanning electron microscopy.
  
  
  RESULTS
  Drug release from levofloxacin-impregnated catheters was rapid. Levofloxacin-impregnated catheters had significantly fewer bacteria compared to PVC in vitro. After first and fifth day of challenge, no or significantly fewer bacteria adhered to impregnated catheters or in surrounding tissues compared to PVC. Scanning electron microscopical images after first day displayed from none to significantly fewer bacteria adhering to impregnated implanted catheters, compared to bacteria and microcolonies adhering to PVC catheters. After the fifth day, no bacteria were found on impregnated catheters, compared to clusters surrounding mucus-like substance and coral-shaped biofilms with polymorphonuclear leukocyte on PVC catheters. After the first day of challenge, secretion occurred in all implanted catheters with surrounding tissues mildly hyperaemic and swollen. After the fifth day, minute secretions inside impregnated catheters and no inflammation in tissues, whereas purulent secretion inside PVC catheters and abscesses in surrounding tissues.
  
  
  CONCLUSIONS
  Levofloxacin-impregnated catheter is a promising new strategy for prevention of catheter-related Psuedomonas aeruginosa infection.
authors.affiliation: Guangxi Institute of Respiratory Diseases, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yan
authors.affiliation: School of Pharmaceutical Sciences, Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Guangxi Institute of Respiratory Diseases, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Kong
authors.affiliation: Department of Clinical Microbiology, Rigshospitalet, University Hospital of Copenhagen, Denmark.
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.affiliation: Guangxi Institute of Respiratory Diseases, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China. Email: chenyq163@tom.com.
authors.forename: Yiqiang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D018441:Biofilms / Q000187:drug effects; D002408:Catheters, Indwelling / Q000382:microbiology*; D005260:Female; D064704:Levofloxacin / Q000627:therapeutic use*; D051379:Mice; D011552:Pseudomonas Infections / Q000517:prevention & control*; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity*
chemical_list: D064704:Levofloxacin