Staphylococcus aureus (SA) bacteremia is associated with
high mortality, and often results in metastatic infections.
The methicillin-resistant SA (MRSA) is an urgent health
care issue, as nosocomial infections with these bacteria
represent limited treatment alternatives. Samples of whole
blood containing challenge inoculums of SA and MRSA
strains were passed through columns packed with surfaceheparinized
polyethylene beads. The bound bacteria were
eluted and quantitatively determined by culturing and by
real-time PCR. Significant amounts of both SA and
MRSA adhered to the heparinized beads (more than 65%
of inoculated bacteria). After rinsing with buffer at high
ionic strength, viable bacteria or bacterial DNA were
eluted from the columns, indicating that the binding was
specific. The conclusions that can be made from these
experiments are that, as earlier reported in the literature,
the high affinity of SA to heparin is retained in whole
blood, and MRSA in whole blood binds to heparin with
similar or higher affinity than SA. It should be possible to
lower the amount of SA and/or MRSA from the blood of
infected patients to levels that could be taken care of by
the immune system. In previous studies, we have shown
that passing blood from septic patients over beads coated
with end-point-attached, biologically active heparin is a
useful technique for regulating the levels of heparinbinding
cytokine. These findings in combination with the
present findings indicate the possibility of creating an
apheresis technology for treatment of sepsis caused by SA
and/or MRSA.

Keywords: Immobilized heparin, bacteria, Staphylococcus aureus, MRSA, aphaeresis