Neuraminidase decreases in vitro adherence of slime-forming coagulase-negative staphylococci to biosynthetic ovine collagen vascular graft

Abstract

Vascular prosthetic graft infection is a major complication of vascular surgery that starts with adhesion of the microorganism to the graft. Because slime-forming microorganisms are the major causative agents in graft infection, the goals of investigators in this study were (1) to investigate the bacterial adherence of slime-forming and non-slime-forming coagulase-negative staphylococci (CNS), and (2) to determine the role of neuraminidase (NANase) in bacterial adherence to the biosynthetic ovine collagen graft. Human plasma was instilled and incubated at 37 degrees C in preparation for fibrin deposition of grafts. After 48 hours, incubation grafts were drained and inoculated with slime-forming and non-slime-forming CNS in tryptic soy broth in the presence and in the absence of neuraminidase. After 24 hours of incubation at 36 degrees C, grafts were vortexed and cultured for colony count. Bacterial counts were expressed as total colony-forming units per longitudinal centimeter of the graft. Slime-forming CNS had greater affinity to the collagen graft compared with non-slime-forming CNS (P<.05). Adherence of slime-forming CNS was impaired by NANase treatment (P<.001). NANase treatment of patients with non-slime-forming CNS did not change adherence to the graft (P>.05). Results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming CNS can be decreased through the administration of NANase. This may have implications for the development of neuraminidase-embedded vascular grafts designed to reduce the occurrence of biomaterial-related infection.