Influence of bacteriophage P22 on the inflammatory mediator gene expression in chicken macrophage HD11 cells infected with Salmonella Typhimurium

This study was designed to evaluate the effects of bacteriophage on the intracellular survival and immune mediator gene expression in chicken macrophage-like HD11 cells. The invasive ability and intracellular survival of Salmonella Typhimurium (STP22-) and lysogenic S.Typhimurium (STP22+) in HD11 cells were evaluated at 37 degrees C for 24h postinfection (hpi). The expression of inflammatory mediator genes was determined in STP22-- and STP22+-infected HD11 cells treated with and without bacteriophage P22 at 1 and 24hpi using quantitative RT-PCR. The ability of STP22- and STP22+ to invade HD11 cells was significantly decreased by bacteriophage P22 at 1hpi. The numbers of intracellular STP22- and STP22+ were significantly decreased from 2.39 to 1.62CFUcm(-2) and from 3.40 to 1.72CFUcm(-2) in HD11 cells treated with bacteriophage P22, respectively, at 24hpi. The enhanced expression of inflammatory mediators was observed in STP22-- and STP22+-infected HD11 cells treated with and without bacteriophage P22. These results suggest that the application of bacteriophage could be an effective way to control the intracellular infection.