Acute phase response to Salmonella in a pig liver perfusion model

Livers from 7- to 14-day old pigs were maintained on a perfusion apparatus for 3 h. The perfused livers maintained physiologic and immunologic functions during perfusion. The perfused livers retained 78–94% of a non-recirculating inoculum of approximately 1–5 × 108Salmonella choleraesuis (Scs), and cleared 94.9 ± 1.7% of the retained (Scs) during the 3-h perfusion period. When the acute phase response (APR) was induced in liver donor pigs 24 h before liver perfusion, the perfused livers had diminished capability to retain, and greatly diminished capability to clear Scs. When sterile, filtered, and concentrated liver perfusate (LP) from previous, LPS-perfused livers was added to the perfusion fluid (PF) at 50 min of Scs perfusion (passive APR), Scs clearance was inhibited. When sterile, filtered LP from previously Scs perfused livers was added to the system, liver clearance was abolished, and Scs always grew in such livers during the 3 h perfusion period. The LP of livers perfused with Scs enhanced growth of Scs in an in vitro assay. These observations suggest that products of the acute phase response favor growth of Scs in vitro and in vivo.