Figure 8.

The working hypotheses are i) the well-formed biofilms in catheters with the single organism, Staphylococcus epidermidis (SE) or Candida tropicalis (CT), consisting of high microbial burdens in catheters (4+) with less biofilm matrix (1+) leading to the low microbial burdens in blood (1+); ii) the poorly formed biofilms in SE simultaneously mixed with CT (SE + CT), consisting of lower organisms in catheters (1+) with similar biofilm matrix (1+), resulting in higher blood microbial burdens (2+) compared with single-organism biofilms but not enough to induce severe sepsis; and iii) fungal interference upon preformed SE biofilms stimulates ECM synthesis of SE with less stable biofilm structure causing higher fungemia (3+), macrophage hyper-responsiveness, and severe sepsis than other groups.