title: Efficacy of tigecycline and vancomycin in experimental catheter-related Staphylococcus epidermidis infection: microbiological and electron microscopic analysis of biofilm.
abstract: Central venous catheters are frequently used. The commonest cause of catheter-related bloodstream infections (CRBSI) is coagulase-negative staphylococci (CoNS) associated with adherent biofilm. Tigecycline, a derivative of tetracycline, acts against strains producing biofilm. In this study, we aimed to determine the effect of tigecycline in a CRBSI model. A single dose of 10(8) colony-forming units (CFU)/mL of slime-producing Staphylococcus epidermidis was given through polyethylene catheters inserted into 24 rabbits. After 72 h, groups of eight rabbits were treated with heparin, vancomycin/heparin or tigecycline/heparin. Blood obtained from peripheral veins and the catheter lumen as well as catheter tips were cultured, and three catheters from each group were studied using electron microscopy. Surfaces were randomly subdivided and areas with ≥50 bacteria were compared. Blood cultures were positive from all heparin-treated rabbits but were negative from those receiving either antibiotic (P<0.001). Catheter tip cultures revealed growth from six, two and one rabbit(s) given heparin, vancomycin and tigecycline, respectively. Electron microscopy showed that catheters from heparin-treated rabbits were most heavily colonised (more areas with ≥50 CFU) compared with catheters from animals treated with vancomycin or tigecycline (P<0.003 and P<0.001, respectively). In conclusion, this study shows that tigecycline and vancomycin are both effective for treating CRBSI due to CoNS. Electron microscopy of catheters themselves suggests that tigecycline is superior to vancomycin (P<0.001). Tigecycline may be useful for the treatment of CRBSI.
authors.affiliation: Department of Infection, Istanbul University, Cerrahpaşa Medical School, Cerrahpasa, Istanbul, Turkey.
authors.forename: Yesim
authors.initials: Y
authors.lastname: Aybar
authors.forename: Resat
authors.initials: R
authors.lastname: Ozaras
authors.forename: Kazim
authors.initials: K
authors.lastname: Besirli
authors.forename: Ersoy
authors.initials: E
authors.lastname: Engin
authors.forename: Ebru
authors.initials: E
authors.lastname: Karabulut
authors.forename: Tamer
authors.initials: T
authors.lastname: Salihoglu
authors.forename: Bilgul
authors.initials: B
authors.lastname: Mete
authors.forename: Fehmi
authors.initials: F
authors.lastname: Tabak
authors.forename: Ali
authors.initials: A
authors.lastname: Mert
authors.forename: Gulgun
authors.initials: G
authors.lastname: Tahan
authors.forename: M Halit
authors.initials: MH
authors.lastname: Yilmaz
authors.forename: Recep
authors.initials: R
authors.lastname: Ozturk
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D018441:Biofilms; D001769:Blood / Q000382:microbiology*; D055499:Catheter-Related Infections / Q000188:drug therapy* / Q000382:microbiology; D002405:Catheterization, Central Venous; D057785:Catheters / Q000382:microbiology; D046508:Culture Techniques; D004195:Disease Models, Animal; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008911:Minocycline / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D011817:Rabbits; D013203:Staphylococcal Infections / Q000097:blood / Q000188:drug therapy / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D000078304:Tigecycline; D013997:Time Factors; D014640:Vancomycin / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D000078304:Tigecycline; D006493:Heparin; D008911:Minocycline