Bacterial translocation across ePTFE vascular graft surfaces.
OBJECTIVE
Vascular graft infections arise from bacterial colonization of either the external or internal graft surfaces. We assessed whether methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli could translocate through pores of ePTFE grafts.


METHODS
To assess translocation from the internal to the external surface, we placed 10(5) cfu of bacterial suspension inside ePTFE graft segments and suspended them in sterile broth for 72 h. To assess translocation from the external to the internal surface, we placed sterile broth inside ePTFE segments, and incubated them for 72 h in a bacterial suspension (10(5) cfu/mL). At 72 h, in addition to culturing the sterile broth and bacterial suspensions, the external and internal surfaces were first qualitatively cultured separately and then quantitatively cultured by sonication.


RESULTS
At 72 h, the sterile broth remained sterile. The bacterial suspensions yielded 10(7)-10(9) cfu/mL. Graft cultures indicated that colonization of one surface with either organism did not result in bacterial translocation to the other surface. Quantitative bacterial counts of the external vs. internal surfaces were significantly different (p < 0.01).


CONCLUSIONS
MRSA and E. coli do not translocate across ePTFE graft surfaces. These in-vitro findings help elucidate the pathogenesis of graft infections and prompt conduction of validation studies in-vivo.
Narasimhan
Supriya
S
Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. narasimh@bcm.edu
Aslam
Saima
S
Lin
Peter H
PH
Bechara
Carlos F
CF
Mansouri
Mohammad D
MD
Darouiche
Rabih O
RO
D018988:Bacterial Translocation; D001807:Blood Vessel Prosthesis / Q000382:microbiology*; D015169:Colony Count, Microbial / Q000379:methods; D004926:Escherichia coli / Q000502:physiology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000502:physiology*; D011138:Polytetrafluoroethylene
D011138:Polytetrafluoroethylene