Phagocytosis and intracellular killing of Campylobacter jejuni by elicited chicken peritoneal macrophages.

In vitro phagocytosis and intracellular survival of Campylobacter jejuni (strains B540 and Clin 1) in chicken peritoneal macrophages were studied. Macrophages were induced with Sephadex G-50 and harvested 48 hr later by peritoneal lavage. The extent of phagocytosis over time was determined by enumerating the intracellular C. jejuni after removal of extracellular C. jejuni with gentamicin. Pre-incubation of C. jejuni with antiserum generally enabled the macrophages to ingest greater numbers of cells than when the organism was pre-incubated in phosphate-buffered saline. C. jejuni were exposed to macrophage uptake for 30 minutes in a 5% CO2 incubator at 42 C. This suspension was then exposed to 12.5 micrograms gentamicin/ml to eliminate extracellular bacteria. Subsequently, the intracellular survival of C. jejuni was examined by monitoring its number within the macrophage at 30 minutes, 3 hr, and 6 hr after phagocytosis. Macrophages from C. jejuni-colonized chickens and from uncolonized control chickens were able to almost destroy the organism within the experimental period.