Differential reactive oxygen and nitrogen production and clearance of Salmonella serovars by chicken and mouse macrophages

The objective of the present study was to compare the uptake and killing of Salmonella serovars by murine and avian macrophage cell lines. We used Salmonella enterica serovars Enteritidis (SE338) and Typhimurium (SR11) for this study. Uptake of green fluorescent protein-labeled bacteria was measured using flow cytometry. Cell sorting and plating of viable infected macrophages demonstrated that bacterial clearance was significantly better with J774A.1 compared with HD11 cells. HD11 cells produced significantly higher amounts of nitric oxide (NO) than J774A.1 cells upon infection with SE338 and SR11, whereas J774A.1 cells exhibited greater superoxide production with SR11. Treatment of HD11 cells with recombinant chicken interferon gamma in the absence of bacteria enhanced NO production but did not induce increased levels synergistically with bacteria. Interferon treatment did not influence phagocytosis or increase killing by HD11 cells.