Furthermore, in at least one vaccine, it is likely that the vaccine strain has an increased association

with leukocytes – the protection of poultry against fowl typhoid is based on the rough strain of Salmonella enterica serovar Gallinarum, which may have a modified tropism similar to what we showed for the rfaL and rfaC mutants of S. Enteritidis (Matiasovic ERK inhibitor library et al., 2011). In this study, we were therefore interested in determining whether attenuated mutants, which are frequently tested as live-attenuated Salmonella vaccines, may have an increased or a decreased tropism for a particular subpopulation of porcine peripheral white blood cells (WBC). The initial aim was to use this information for the future design of improved live Salmonella vaccines for the protection of animals against S. enterica infection. However, on analyzing the results, we realized that the same information might also be useful in two additional see more cases. Firstly, it can be used when selecting the most suitable S. enterica mutant as a vector for the targeted expression of heterologous antigen(s). Secondly, because S. enterica has also been used for cancer therapy (Zhao et al., 2005; Stritzker et al., 2010), modification of its preference for particular cells

may influence either

its delivery to the site of the tumor or its very interaction with tumor cells. Salmonella enterica serovar Enteritidis strain 147 spontaneously tuclazepam resistant to nalidixic acid was used in this study (Methner et al., 2004). The construction of isogenic aroA, phoP, rfaL, rfaG, rfaC and fliC mutants and the ΔSPI1-5 mutant has been described previously (Karasova et al., 2009; Rychlik et al., 2009), except for the fact that all the strains used in this study were transformed with the pFPV25.1 plasmid constitutively expressing green fluorescent protein (GFP) (Valdivia & Falkow, 1996). The strains were subcultured in Luria–Bertani (LB) broth or LB agar at 37 °C. All these procedures have been described previously (Matiasovic et al., 2011). Briefly, peripheral blood was taken from the vena jugularis of four healthy pigs that were 3 months of age. After erythrocyte lysis and washing the leukocytes twice with Dulbecco’s phosphate-buffered saline, WBC were resuspended in Hank’s balanced salt solution at a concentration of 107 cells mL−1. If necessary, porcine heat-inactivated serum (Gibco) was added to the WBC preparation to reach a 10% concentration. WBC were infected with S. Enteritidis to reach a multiplicity of infection equal to 10.