Project description:Poultry products are an important source of Salmonella enterica. An effective way to reduce food poisoning due to Salmonella would be to breed chickens more resistant to Salmonella. Unfortunately resistance to Salmonella is a complex trait with many factors involved. To learn more about Salmonella resistance mechanisms in young chickens, a cDNA microarray analysis was performed to compare gene expression profiles between a Salmonella susceptible and a more resistant chicken line. Newly hatched chickens were orally infected with S. enterica serovar Enteritidis. Since the intestine is the first barrier the bacteria encountersbacteria encounter after oral inoculation, gene expression was investigated in the intestine, from day 1 until day 21 post infection. Differences in gene expression between the susceptible and resistant chicken line were found in control as well as Salmonella infected conditions. In response to the Salmonella infection, the expression of different sets of genes seemed to be affected in the jejunum of the two chicken lines. In the susceptible line this included genes that affect T-cell activation, whereas in the more resistant line, at day 1, macrophage activation seemed to be more affected. At day 7 and 9 most gene expression differences between the two chicken lines were identified under control conditions, indicating a difference in the intestinal development between the two chicken lines which might be linked to the difference in Salmonella susceptibility. The findings in this study have lead to the identification of novel genes and possible cellular pathways of the host involved in Salmonella susceptibility. Keywords: timecourse, disease
Project description:S. enterica sv Kentucky 3795 and S. enterica sv Enteritidis NalR were grown to mid-log phase in TSB, then subjected to three different acidic conditions generated by two different acids: HCl to pH4.5, HCl to pH5.5 and CH3COOH to pH5.5. After 10min, total RNA was harvested und compared to total RNA harvested from identical control cultures grown in TSB without the pH alteration. At least three biological replicates were performed for each strain and acidic condition. Total RNAs were harvested, and labeled by the conventional protocol of Brown et al, then hybridized onto a Salmonella-specific PCR product array that covered over 97% of the Enteritidis genome.
Project description:Transcriptional profiling of jejunum infected with Salmonella in three different chicken lines early in life. Samples were taken at 8, 24 and 48 hours post infection. Salmonella was orally ingested at day zero (hatch).
Project description:Salmonella enterica is one of the most important foodborne pathogens that infect a variety of animals and birds. In humans, S. Typhimurium causes gastroenteritis, leading to vomiting, diarrhea, fever, and abdominal cramps. We mainly get infected with Salmonella by ingesting comminated poultry products. Therefore, developing an oral live attenuated vaccine for the poultry industry is our best bet against Salmonella infection. In this article, we investigated the potential of the next generation of Salmonella vaccines. We generated a library of potentially attenuated S. Typhimurium mutants and compared fitness to that of a commercial vaccine. We also investigated the invasion and survival potential of these mutants in chicken macrophages. Our data indicate that although these mutants had no significant growth defects, they were much sensitive to macrophage attack. Analyzing the transcriptome data from infected primary chicken macrophages, we concluded that these mutants elicit a robust immune response by activating several immunoregulatory pathways. Our data also indicates that by combining phoPQ deletion with an already existing cya-crp deletion in MeganVac1, a much stronger immune response can be generated.